Science of the Total Environment 482-483 (2014) 501–509
Contents lists available at ScienceDirect
Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv
Soundscape in the sustainable living environment: A cross-cultural comparison between the UK and Taiwan Chia-Jen Yu a,⁎, Jian Kang b a b
Department of Design for Sustainable Environment, College of Design, MingDao University, 369 Wen-Hua Rd., Peetow, ChangHua 52345, Taiwan School of Architecture, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
H I G H L I G H T S • • • • •
When choosing a living environment, factor ‘quiet’ is an important consideration The acoustic environment in Taipei is less comfortable than in Sheffield In both cities there is a high percentage of activities which are disturbed by noise For noise noticeability, there are considerable differences between two cities For noise annoyance and sound preference, there are significant cultural differences
a r t i c l e
i n f o
Article history: Received 1 May 2013 Received in revised form 3 October 2013 Accepted 28 October 2013 Available online 27 November 2013 Keywords: Soundscape Noise Perception Culture Urban Residential areas
a b s t r a c t This study examines the effects of cultural factors on the evaluation of acoustic quality of residential areas, within the context of general environmental conditions. A comparative study was carried out between the UK and Taiwan, through questionnaire surveys at three stages, namely in selected residential areas, with respondents in their place of work/study, and using a web-based survey, respectively. This study reveals the importance of considering cultural factors, as well as their living experiences. This is reflected by the significant differences between the two cultures in a number of aspects, including choosing and evaluating living environment, noise noticeability, annoyance and sleep disturbance, activities, and sound preference. It is interesting to note the factor ‘quiet’ is an important consideration compared to other factors, in both the UK and Taiwan. Crown Copyright © 2013 Published by Elsevier B.V. All rights reserved.
1. Introduction Globally, urban living has become increasingly widespread, seriously affecting urban sustainable development. Consequently, sound quality in our living environment is becoming ever more important, while the noise level is continuously increasing (Kuwano et al., 1999; Kang, 2006). In terms of sound quality, three factors should be considered: compatibility of the sounds, pleasantness of the sounds as well as identifiability of sounds (Guski, 1997). Social and demographic factors of the users may also play an important role in soundscape evaluation (Kang, 2006), as well as sound sensitivity of individuals (Zimmer and Ellermeier, 1999). Moreover, differences in urban texture, including building density, dimensions and boundaries of the areas can lead to different urban sound fields, which is an important consideration in assessing the sound environment (Kang, 2006).
In terms of urban acoustics sustainability, people's perception is an important factor (Yu, 2008). This is examined in this study through a comparative study in urban residential areas. Typical urban residential areas in the UK and Taiwan have been selected for comparison, considering differences in culture as well as urban texture. The main aim is to examine how people perceive their sound environment in the context of current situations of their living areas, and to identify the comfortable and pleasant sounds in terms of developing sustainable environments. This paper first introduces the survey methods at three stages. It then analyses the survey results in terms of choosing a living environment, effect of social and demographic factors when choosing a living environment, current living environment, environmental pollution, main activities, noise noticeability, annoyance, and sleep disturbance, and sound preference. 2. Methodology
⁎ Corresponding author. Tel.: +886 4 8876660. E-mail address: [email protected] (C.-J. Yu).
Two cities, Sheffield in the UK and Taipei in Taiwan, were selected for the comparative study. While the two cities are different in urban
0048-9697/$ – see front matter. Crown Copyright © 2013 Published by Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.scitotenv.2013.10.107
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C.-J. Yu, J. Kang / Science of the Total Environment 482-483 (2014) 501–509
Table 1 Situations of the case study sites, three in Sheffield, UK and three in Taipei, Taiwan.
Shef
Site
Land
House
Traffic/hour
Springvale Rd. Highton St. Cavendish St.
Sloped:1/12 Sloped:1/7 Sloped:1/20
Detached/terraced Detached/terraced Flat
57 54 84
texture, they both represent typical cities. The comparative study was carried out through a questionnaire survey at three stages. At stage one, on-site questionnaire surveys and interviews were made in six representative residential areas — three in Sheffield and three in Taipei. At stage two, a questionnaire survey was carried out in both Sheffield and Taipei with respondents in ten places of work/study in each city. At stage three, a web-based survey was carried out in both the UK and Taiwan. At stages one and two an identical questionnaire was used, which was designed to ascertain people's satisfaction with their living environment, including how they perceived environmental pollution and the quality of the ambient sound, and the identification of preferred sounds. The questionnaire at stage three had the same structure as that at stages one and two but fewer questions were included. At each stage, the questionnaire was in English in the UK and in Chinese in Taiwan and they were identical in context. A five-point linear scale was generally used in the questionnaire, for example, from −2, very uncomfortable, to 2, very comfortable. During the three stages of questionnaire survey, there were 80, 200 and 300 respondents, respectively. Over three stages, all respondents were selected at random, and the statistical analysis using software SPSS (2005) shows that the distribution of occupation, education, gender, and age was largely representative (Yu, 2008). In the analysis below, if the number of people in any group is fewer than 10, this group will be treated as missing data when comparing differences between groups. Table 1 shows the characteristics of the six residential areas at stage one, three in Sheffield and three in Taipei. The sites were selected to
Springvale Road
JianGuo S Road
Highton Street
GuoXing Road
TP
Site
Land
House
Traffic/hour
JianGuo S Rd. GuoXing Rd. ZhangXing E Rd.
Flat Flat Flat
Flat Flat Flat
8837 3861 7335
represent typical urban textures as well as residents' social, demographic and cultural backgrounds. Sound pressure level (SPL) measurements were made considering various typical time periods, and noise maps were made using software Cadna (2007). Whilst the traffic data and building heights used in the noise mapping were obtained through on-site observations and measurements, the calculation parameters in the noise maps were calibrated through comparisons between measured and calculated SPL. The noise maps of the six case study sites are shown in Fig. 1. 3. Results 3.1. Choosing a living environment Previous studies have shown that regional differences, including cultural heritage, construction methods, lifestyle and weather, may influence noise annoyance (Kang, 2006; Gjestland, 1998; Huang, 2004). The economic effects of community noise have also been examined, especially from the viewpoint of compensation payable on depreciation in property value. Such depreciations can be attributed to noise among other physical factors (Rosen, 1974; Walters, 1975; Nelson, 1982; Hufschmidt et al., 1983; Turner et al., 1994; Hawkins, 1999; Bateman et al., 2001; Navrud, 2002; Wardman and Bristow, 2004). Consequently, in this study, questions were asked about the importance of various factors when people choose a living environment. As mentioned above, a five-level linear scale was used, from −2, do not mind, to 2, very important. The results of stages one and two are shown in Fig. 2. Through
Cavendish Street, Sheffield
ZhangXing E Road, Taipei
Fig. 1. Plan of the case study sites in Sheffield and Taipei and corresponding noise-maps.
C.-J. Yu, J. Kang / Science of the Total Environment 482-483 (2014) 501–509
503
Fig. 2. Importance of various factors when choosing a living environment.
the Independent Samples Test, it can be seen that there are generally significant differences (p b 0.01) between the two cities for both stages one and two. It seems that respondents in Taipei gave considerably higher scores, by about 0.6 points on average, than the respondents in Sheffield, which might be a reflection of cultural differences, although in both cities the standard deviations (Std.) are relatively high compared to the mean value. In terms of the order of importance of various factors, from Fig. 2 it can be seen that there are similarities between the two cities in the first stage. For example, safety is at the top of both lists at both stages one and two. It is interesting to note that at stage one the factor ‘quiet’ is ranked as the 4th most important factor in Sheffield, and 3rd in Taipei, suggesting that in both cities, the sound environment is an important consideration compared to other factors. At stage two ‘quiet’ is ranked as the 6th important factor in Sheffield, and 4th in Taipei. The correlation coefficient between the two rankings is R2 = 0.57 at stages one and R2 = 0.46 at stage two. 3.2. Effect of social and demographic factors when choosing a living environment Social and demographic factors are important considerations when studying the subjective evaluation, although results of previous studies varied (Fields, 1993; Miedema and Vos, 1999; Rylander et al., 1972; Sato, 1993; Tonin, 1996; Yang and Kang, 2005a,b). Differences between
various education levels, age groups, current living environments, sleep quality, gender and occupations were examined in this study, and some results are shown in Table 2. It can be seen that for some factors including recreational space, sociable neighbourhoods, views, and more importantly for this study, quietness, there are significant effects from social and demographic factors, whereas in terms of convenience for work and interior decoration, the effects from social and demographic factors are generally insignificant. Between Sheffield and Taipei, it seems that the effects from social and demographic factors in the former were slightly higher. In terms of the effects of the above social and demographic factors on the evaluation of ‘quiet’ when choosing a living environment, Fig. 3 shows the results of stage two. In terms of occupation, as shown in Fig. 3e, in Sheffield there were significant differences between students, working people (people in employment) and pensioners (p b 0.01), with mean evaluation scores of 0.11, 0.83 and 1.58 respectively, whereas in Taipei such differences are not significant. In terms of current living environment, as shown in Fig. 3c, in Sheffield there is a slight trend that with a better current environment, people tend to think ‘quiet’ is more important, with a correlation coefficient of 0.166. In Taipei there is no such tendency. In terms of age, it is interesting to note in Fig. 3b that the age group 18–24 has a significantly lower score than that of the other groups (p b 0.000) in Sheffield, whereas in Taipei the differences between different age groups are not significant. The effects of education level and gender are generally not statistically significant, although
Table 2 Significance level of the correlations between occupation, education level, age, current living environment and choosing a living environment, where p b 0.01 are marked with ** and p b 0.05 marked with *. Sig. (2-tailed) Occupation
Stage 1 Stage 2
Education
Stage 1 Stage 2
Age
Stage 1 Stage 2
Current living
Stage 1 Stage 2
Shef TP Shef TP Shef TP Shef TP Shef TP Shef TP Shef TP Shef TP
Convenience for work
Convenience: transport
Convenience: school shopping
Recreational space
Sociable neighborhoods
Safety
Property price
Quiet
Views
Size of the house
Interior decoration
0.12 0.10 0.01** 0.46 0.80 0.98 0.59 0.86 0.39 0.19 0.27 0.44 0.15 0.91 0.01** 0.22
0.05 0.10 0.00** 0.36 0.10 0.98 0.01** 0.82 0.07 0.19 0.00** 0.24 0.56 0.91 0.54 0.17
0.91 0.14 0.21 0.16 0.04 0.67 0.00** 0.87 0.43 0.50 0.05* 0.94 0.64 0.04* 0.55 0.02*
0.00** 0.02* 0.00** 0.00** 0.00** 0.38 0.00** 0.23 0.01* 0.09 0.00** 0.07 0.88 0.07 0.79 0.03*
0.03* 0.46 0.00** 0.48 0.00** 0.01** 0.00** 0.16 0.09 0.47 0.01* 0.15 0.02* 0.11 0.00** 0.07
0.71 0.54 0.45 0.23 0.94 0.67 0.82 0.26 0.30 0.83 0.03* 0.78 0.06 0.39 0.00** 0.07
0.10 0.11 0.01** 0.86 0.13 0.71 0.02* 0.24 0.00** 0.43 0.00** 0.70 0.17 0.65 0.03* 0.46
0.02* 0.55 0.00** 0.19 0.13 0.91 0.01** 0.74 0.00** 0.52 0.00** 0.83 0.22 0.55 0.02* 0.60
0.02* 0.93 0.00** 0.12 0.44 0.17 0.16 0.05* 0.00** 0.67 0.00** 0.69 0.05 0.12 0.00** 0.13
0.24 0.95 0.05** 0.24 1.00 0.06 0.91 0.00** 0.00** 0.17 0.00** 0.45 0.17 0.01** 0.02* 0.03*
0.37 0.62 0.14 0.20 0.31 0.06 0.13 0.10 0.76 0.74 0.49 0.47 0.53 0.01* 0.41 0.01**
504
C.-J. Yu, J. Kang / Science of the Total Environment 482-483 (2014) 501–509
a
b
2
2
Evaluation
-1
-2
-2 18
-1 7 11
U
ni ve
le v A
O
le v
el
rs ity
-1
-2 4 -3 4 35 -4 4 45 -5 4 55 -6 4 >6 5
0
25
0
el
Evaluation
1 1
Education
Age
c
d
2
Evaluation
1 0 -1 -2
1 0 -1
ye no
an y
er
er
V
V
er N
ei
th
d
ed
m
oy nn
A
M
ed
iu
d fie tis
y
V
sa
er
tis
y
fie
ba
d
d
d Ba
ba or
w
V
el
er
ln
y
w
W
el
l
el
l
d
-2 Sa
Evaluation
2
Living environment
e
Sleeping quality
f
2 1
Evaluation
1 0
0 -1
-1
al e Fe m
al
er s th O
W
St ud or en ki t ng pe rs on Pe ns io ne H ou r se ke ep er
e
-2
-2
M
Evaluation
2
Occupation
Gender
Fig. 3. Effects of social and demographic factors when choosing a living environment, in terms of ‘quietness’, based on the results of stage two. Black bars: UK; white bars: Taipei.
there are some differences in the mean evaluation scores, as shown in Fig. 3a and f, respectively. It is somewhat unexpected that the correlation between sleep quality and choosing a quiet environment is not high, as can be seen in Fig. 3d. 3.3. Current living environment Table 3 compares the perception of respondents in Sheffield and Taipei of their general living environment, sound quality of their living area, and sound quality at home, where five-point linear scales were again used, from 1, comfortable, to 5, very uncomfortable. The results of stage one, two and three all show that the scores in Taipei are significantly higher than those in Sheffield, by about 0.5–0.7, indicating that the general living condition/environment and the acoustic environments in Taipei are less comfortable in terms of people's perception.
For sound environment, it is interesting to note that this corresponds to the noise level difference between the two cities, as shown in Fig. 1, which is about 10 dBA. In Table 3 the evaluation of general health level is also examined based on results at stages one and two. The results correspond to the evaluation of their living environment and sound quality. Taipei residents also found their health condition less satisfactory compared to that in Sheffield, with a difference of 0.79 in the mean evaluation score at stage one and 0.72 at stage two. 3.4. Environmental pollution Whilst the importance of sound quality and quietness has been demonstrated above, in the questionnaire the respondents were asked to rank the four pollutions, namely water, air, noise and waste. The
C.-J. Yu, J. Kang / Science of the Total Environment 482-483 (2014) 501–509
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Table 3 Evaluations of living environment and sound quality of the living area and home. Stage 1
General living environment Sound quality of living area Sound quality of home Health
Mean Std. Mean Std. Mean Std. Mean Std.
Stage 2
Shef
TP
Shef
TP
UK
TW
1.81 0.53 2.16 0.65 1.95 0.53 1.75 0.83
2.43 0.9 2.44 0.93 2.59 0.88 2.54 0.75
1.82 0.53 1.79 0.86 2.13 0.6 1.97 0.53
2.36 0.87 2.49 0.78 2.65 0.96 2.69 0.89
2.26 0.71 2.23 0.88 2.25 0.93
2.65 0.79 2.95 0.88 2.74 0.75
stage one and two results are shown in Table 4. For example, the mean ranking order at stage one is: air, 2.09; noise, 2.12; waste, 2.53; water, 3.26, in Sheffield, and air, 2.29; noise, 2.33; water, 2.81; waste, 2.94, in Taipei. It is important to note that at stage one, both Sheffield and Taipei noise were perceived as the second serious pollutant, with a slightly lower score than air pollution, and at stage two, noise is even perceived as the first serious pollutant in Sheffield. The importance of noise pollution in the overall sustainable urban environment has also been demonstrated by other researchers (Peyton, 2005; Cowell, 2005). 3.5. Main activities Since noise may be more disturbing for certain activities, such as oral communication, listening to radio and intellectual tasks, than for other activities, the main activities of the respondents when they stay at home were asked about, and in the questionnaire multiple choices were allowed. The results of three stages are shown in Table 5. It can be seen that in both cities there was a high percentage of activities which could potentially be disturbed by noise. It seems that there were high percentages of reading and music in Sheffield than those in Taipei, suggesting that Sheffield people could be more sensitive in terms of disturbance of activities. Between stage one and stage two there is an insignificant difference in both cities. 3.6. Noise sources: noticeability, annoyance, and sleep disturbance Noise annoyance may increase if a neighbourhood is perceived in a negative way, and it is also influenced by the life-style chosen by certain people, for whom a certain quantity of noise is part of their life. Moreover, people may get used to certain noises and thus become less annoyed (Kang, 2006). Consequently, various sources in an urban soundscape could have different impacts on people, and this could vary with different cultural environments. In the questionnaire the noticeability, annoyance level and sleep disturbance of typical sound sources in residential areas were examined, where five-point linear scales were again used.
Table 4 Ranking of various types of environmental pollution. Stage 1
Water pollution
Air pollution
Noise pollution
Waste pollution
Mean rank Std. Rank Mean rank Std. Rank order Mean Std. Rank Mean rank Std. Rank
Stage 3
Stage 2
Shef
TP
Sig.
Shef
TP
Sig.
3.26 0.96 4 2.09 0.90 1 2.12 1.20 2 2.53 1.02 3
2.81 1.30 3 2.29 1.01 1 2.33 1.12 2 2.94 1.34 4
0.12
3.06 1.13 4 1.96 0.91 2 1.81 1.12 1 2.20 1.09 3
2.49 1.25 3 1.92 0.97 1 2.08 1.08 2 3.07 1.18 4
0.00
0.95
0.49
0.01
0.78
Difference between Stage 1 & 2 (%)
Difference between Stage 2 & 3 (%)
Shef
TP
Shef-UK
TP-TW
0.50
−3.00
19.47
10.94
−21.00
2.01
19.73
15.59
8.45
2.26
5.33
3.28
In terms of noticeability, the results of stages one and two are shown in Fig. 4. It can be seen that there are generally considerable differences between Sheffield and Taipei, with Taipei having significantly greater scores, namely easier to be noticed. This reflects the difference in noise levels in the two cities. The SPL in the Taipei sites were about 10 dBA higher than those in Sheffield at typical roadside receivers, due to the difference in landform, building types, and more importantly, traffic density. Between the three sites in Sheffield the SPL varied by about 6 dBA, and the variation range in Taipei was similar. Interestingly, in terms of ranking of various noise sources, people living in Sheffield had a greater score in terms of noticeability on traffic noise, especially heavy vehicles, although their SPL was actually much lower than that in Taipei. In Taipei, the noise sources at the top list were two wheelers (i.e. motorcycles), as well as talking, music and TV, from neighbours. According to Guski (1998), the noise annoyance by inhabitants only depends on approximately 33% of the acoustic parameters such as acoustic energy, number of sound events, and length of moments of calm between intermittent noises. The annoyance level and sleep disturbance of stages one and two are shown in Figs. 5 and 6, respectively. It can be seen that the annoyance level generally corresponds to the noticeability level, and the evaluation of sleep disturbance also corresponds to noticeability and annoyance level. In terms of annoyance, traffic noise again ranked highest in Sheffield, whereas in Taipei two wheelers and talking/music/TV were found most annoying, as well as the annoyance caused by nearby events. In terms of sleep disturbance, traffic noise is also at the top of the list in Sheffield, namely was considered most annoying, as well as talking/music/TV, from neighbours, whereas in Taipei two wheelers and talking/music/TV are found most disturbing, as well as heavy vehicles. The evaluation of sleep disturbance generally corresponds to that for noticeability and annoyance. The correlations between noticeability, annoyance and sleep disturbance of stage two are further demonstrated in Figs. 7 and 8, based on the results at stage two. It can be seen that the correlations are high, ranging from 0.72 to 0.95. In both stages one and two, it is particularly interesting to note that the noticeability scores are generally systematically higher than those of annoyance scores, which suggests that although people may notice many sounds, they are not necessarily annoyed, showing people's tolerance. In urban open public spaces similar results are also found (Kang, 2006).
Table 5 Main activities at home (%), where multiple choices were allowed. Stage 1
0.05
0.00
Stage 2
Activities
Shef
TP
Shef
TP
Reading TV Music Others
61 54 55 41
35 85 9 29
63 57 57 45
38 81 5 29
Stage 1 - Sheffield
Stage 1 - Taipei
Nearby events
Stage 2 - Sheffield
Fig. 6. Sleep disturbance of various noise sources in Sheffield and Taipei.
Stage 2 - Sheffield
Self- house air-conditioning
Self- house air-conditioning
Self- house talking, music, TV
Neighbours air-conditioning
Stage 2 - Sheffield
Self- house talking, music, TV
Nearby events Neighbours talking, music, TV
Factors
Neighbours air-conditioning
Stage 1 - Taipei Nearby transportation stations
Stage 1 - Taipei
Nearby transportation stations
Nearby recreation
Nearby shops
Nearby recreation
Nearby shops
Nearby school
Motorbike
Heavy vehicle
Medium vehicle
Light vehicle
Self- house air-conditioning
Self- house talking, music, TV
Neighbours air-conditioning
Neighbours talking, music, TV
Nearby events
Nearby transportation stations
Factors
Neighbours talking, music, TV
Factors
Nearby recreation
Nearby shops
Stage 1 - Sheffield Nearby school
Motorbike
Heavy vehicle
Medium vehicle
Light vehicle
Mean Stage 1 - Sheffield
Nearby school
Motorbike
Heavy vehicle
Medium vehicle
Light vehicle
Mean
Mean
506 C.-J. Yu, J. Kang / Science of the Total Environment 482-483 (2014) 501–509
2 1.5 1 0.5 0 -0.5 -1 -1.5 -2
Stage 2 - Taipei
Fig. 4. Noticeability of various noise sources in Sheffield and Taipei.
2 1.5 1 0.5 0 -0.5 -1 -1.5 -2
Stage 2 - Taipei
Fig. 5. Annoyance of various noise sources in Sheffield and Taipei.
2 1.5 1 0.5 0 -0.5 -1 -1.5 -2
Stage 2 - Taipei
C.-J. Yu, J. Kang / Science of the Total Environment 482-483 (2014) 501–509
a 2
2
1
1
0
Annoyance
Annoyance
a
507
2
R = 0.882
-1
2
R = 0.9545
0 -1
-2 -2
-1
0
1
-2
2
-1
0
Noticeability
b
b Sleep disturbance
Sleep disturbance
2 1 0 R2 = 0.7244
-1 -2
-2
-1
0
1
Sleep disturbance
Sleep disturbance
2 1 0 R2 = 0.9251
-1
1
2
-1
0
2 1
1
2
R = 0.9358
0 -1 -2
0
2
2
R = 0.9139
0
Noticeability
c
-1
1
1
-2 -1
2
c
-2
2
2
Noticeability
-2
1
Noticeability
-1
0
2
Annoyance
Annoyance Fig. 7. Relationships between noise noticeability, annoyance and sleep disturbance in Sheffield, based on the results at stage two.
3.7. Sound preference Urban soundscape includes not only negative, but also positive sounds. Given the effects of various sound sources shown above, and it has been previously demonstrated that positive sounds could improve urban soundscape without necessarily reducing the level of noise sources (Kang, 2006), sound preference was studied through the questionnaire survey, where the respondents were asked to select the sounds they prefer from a list. The results are shown in Table 6, where differences between Sheffield and Taipei are also examined statistically and the significance levels are shown. It is interesting to note that there are generally significant differences in sound preference between Sheffield and Taipei. At stages one and two, the preference level of bird sounds and water sounds is much higher in Sheffield than in Taipei, by 38%, 42% and 20%, 20%, respectively. On the other hand, in Sheffield insect sounds and music from outside were almost not selected, whereas this percentage is 20–25% in Taipei. There are also a higher percentage of people in Sheffield who suggested other preferred sounds.
Fig. 8. Relationships between noise noticeability, annoyance and sleep disturbance in Taipei, based on the results at stage two.
In the stage three study, respondents were asked to select the sounds they would prefer, both in the living area and at home, from a given list, including both natural sounds and artificial sounds. Table 7
Table 6 Preference of various sounds, with 1 as yes (selected) and 2 as no, based on results at stages one and two. Stage 1
Birdsong Insect sounds Water Music from outside Other sounds
Mean Std. Mean Std. Mean Std. Mean Std. Mean Std.
Stage 2
Shef
TP
Sig.
Shef
TP
Sig.
1.3 0.46 1.96 0.19 1.69 0.47 1.96 0.19 1.71 0.46
1.68 0.48 1.79 0.42 1.89 0.32 1.74 0.45 1.89 0.57
0.8
1.28 0.45 1.97 0.18 1.73 0.45 1.96 0.21 1.71 0.45
1.7 0.88 1.93 0.8 1.93 0.96 1.65 0.89 1.94 0.65
0.00**
0.00** 0.00** 0.00** 0.61
0.49 0.01* 0.00** 0.00**
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C.-J. Yu, J. Kang / Science of the Total Environment 482-483 (2014) 501–509
Table 7 Preference of various natural sounds and artificial sounds, with 1 as yes (selected) and 2 as no, based on results at stage three. Area
Natural sounds
Bird songs Water Insect sounds Quiet Others
Artificial sounds
Bells of church Music Traffic sound Others
Mean Std. Mean Std. Mean Std. Mean Std. Mean Std. Mean Std. Mean Std. Mean Std. Mean Std.
Home
UK
Rank
TW
Rank
Sig.
UK
Rank
TW
Rank
Sig.
1.59 0.49 1.71 0.45 1.95 0.23 1.51 0.50 1.97 0.17 1.77 0.42 1.52 0.5 1.95 0.22 1.98 0.13
2
1.49 0.50 1.83 0.37 1.71 0.45 1.41 0.49 2.00 0.00 1.95 0.22 1.83 0.37 1.98 0.14 2.00 0.00
2
0.00**
2
0.00**
0.00**
4
0.00**
3
0.00**
3
0.00**
1
0.00**
1
0.04*
5
0.00**
5
0.00**
2
0.00**
2
0.00**
1
0.00**
1
0.00**
3
0.00**
3
0.25
4
0.00**
1.69 0.46 1.91 0.29 1.78 0.42 1.40 0.49 2.00 0.00 1.99 0.08 1.41 0.49 2.00 0.06 2.00 0.00
2
4
1.76 0.43 1.78 0.41 1.98 0.15 1.44 0.50 1.97 0.16 1.93 0.26 1.31 0.46 1.99 0.08 1.97 0.18
3
0.00**
3 4 1 5 2 1 3 4
shows the results. Through the Independent Samples Test, it can be seen that there are significant differences between the UK and Taiwan for nearly all sounds listed. However, it is interesting to note that in terms of the ranking of sound preference, the differences between the UK and Taiwan are generally insignificant. The correlations between the UK and Taiwan rankings are relatively high, with R2 = 0.5–1. In both the UK and Taiwan, ‘quiet’ is highly preferred both in the living area and at home. This is followed by bird songs and water sounds, although it is interesting to note that these two sounds were less preferred at home compared to the living area, both in the UK and Taiwan. Insect sounds were less preferred in the UK compared to Taiwan, which was similar to the results obtained at stages one and two. Church bells were less preferred in Taiwan compared to the UK, likely caused by cultural differences. Music was generally preferred both in the living area and at home, although the preference level is higher at home. It is interesting that the preference level of music was higher in the UK than that in Taiwan, which corresponds to people's activities, as shown in Table 7. As expected, traffic sounds are generally the least preferred (Kang, 2006). Moreover, it is important to note that the standard deviation for traffic sounds is much less than that for other more preferred sounds. 4. Conclusions The survey results at the three stages show that people's perceptions of their living environment can be affected by different cultural and social factors, as well as their living experiences. In terms of choosing a living environment, it is interesting to note the factor ‘quiet’ is an important consideration compared to other factors. The general living condition/environment and the acoustic environments in Taipei are less comfortable in terms of people's perception, by about 0.5–0.7 in terms of evaluation score at a five-point scale. Besides, Taipei residents also found their health condition less satisfactory compared to residents in Sheffield. In terms of environmental pollution, in both Sheffield and Taipei noise was perceived as a serious pollutant. In both cities there was a high percentage of activities which could potentially be disturbed by noise, and those in Sheffield could be more sensitive in terms of disturbance of activities. In terms of noise noticeability, there are generally considerable differences between Sheffield and Taipei, with Taipei having higher noticeability of noise sources. Among noise annoyance, noticeability and sleep disturbance there are high correlations, and the noticeability level is generally systematically higher than that of annoyance level,
3 5 1 4 2 1 4 3
showing people's tolerance. In terms of annoyance of different noise sources, and also sound preference, there are generally significant differences between Sheffield and Taipei, and between the UK and Taiwan. This study suggests the great importance of considering the cultural differences in noise policies as well as noise abatements measures. With a holistic framework, for example, based on the WHO guidelines (Berglund et al., 1999), different countries/regions could have specific regulations and abatement measures for specific noise sources. It is also important to take the principles of soundscape approaches into account (Kang, 2006), by designing the balance of difference source sources, rather than only reducing noise levels. References Bateman IJ, Day B, Lake I, Lovett AA. The effect of road traffic on residential property values: a literature review and hedonic pricing study. Edinburgh: Report commissioned by the Scottish Executive Development Department; 2001. Berglund B, Lindvall T, Schwela DH. Guidelines for community noise. World Health Organization report; 1999. DataKustik GmbH. Cadna/A for Windows – UserManual.Munich, Germany; 2007. Cowell JR. Sustainable design in acoustics. Proceedings of the Institute of Acoustics; 2005. Fields JM. Effect of personal and situational variables on noise annoyance in residential areas. J Acoust Soc Am 1993;93:2753–63. Gjestland T. Regional differences in noise annoyance assessments. Proceedings of inter-noise; 1998. Guski R. Psychological methods for evaluating sound quality and assessing acoustic information. Acustica united with acta acustica, 83; 1997765–74. Guski R. Psychological determinants of train noise annoyance. Proceedings of euro-noise; 1998. Hawkins R. Review of studies on external costs of noise. Environmental Protection Economics Division of the (former) UK Department for Environment, Transport and the Regions (DETR); 1999. Huang Z. Environmental noise situation of residential areas and the change with city expansion in Xi'an City, China. (MArch dissertation). UK: University of Sheffield, School of Architecture; 2004. Hufschmidt MM, James DE, Meister AS, Browen BT, Dixon JA. Environment, natural systems, and development: an economic valuation guide. Baltimore: John Hopkins University Press; 1983. Kang J. Urban Sound Environment. London: Taylor & Francis incorporating Spon; 2006. Kuwano S, Namba S, Florentine M, Zheng DR, Fastl H, Schick A. A cross-cultural study of the factors of sound quality of environmental noise. Presented at the 137th Meeting of the Acoustical Society of America and Forum Acusticum, Berlin, 105. Abstract published in Journal of Acoustical Society of America; 1999. p. 1081. Miedema HME, Vos H. Demographic and attitudinal factors that modify annoyance from transportation noise. J Acoust Soc Am 1999;105:3336–44. Navrud S. The state-of-the-art on economic valuation of noise. Final Report to European Commission Directorate-General (DG) Environment; 2002. Nelson JP. Highway noise and property values: a survey of recent evidence. J Transp Econ Policy 1982;16:117–38. Peyton CH. Creating through sustainable design. Proceedings of the Institute of Acoustics; 2005.
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Walters AA. Noise and prices. London: Oxford University Press; 1975. Wardman M, Bristow AL. Noise and air quality valuations: evidence from stated preference residential choice models. Transp Res 2004;9:1–27. Yang W, Kang J. Acoustic comfort evaluation in urban open public spaces. Appl Acoust 2005a;66:211–29. Yang W, Kang J. Soundscape and sound preferences in urban squares. J Urban Des 2005b;10:69–88. Yu C. Environmentally sustainable acoustics in urban residential areas. (PhD dissertation) UK: University of Sheffield, School of Architecture; 2008. Zimmer K, Ellermeier W. Psychometric properties of four measures of noise sensitivity: a comparison. J Environ Psychol 1999;19:295–302.
Contents lists available at ScienceDirect
Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv
Soundscape in the sustainable living environment: A cross-cultural comparison between the UK and Taiwan Chia-Jen Yu a,⁎, Jian Kang b a b
Department of Design for Sustainable Environment, College of Design, MingDao University, 369 Wen-Hua Rd., Peetow, ChangHua 52345, Taiwan School of Architecture, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
H I G H L I G H T S • • • • •
When choosing a living environment, factor ‘quiet’ is an important consideration The acoustic environment in Taipei is less comfortable than in Sheffield In both cities there is a high percentage of activities which are disturbed by noise For noise noticeability, there are considerable differences between two cities For noise annoyance and sound preference, there are significant cultural differences
a r t i c l e
i n f o
Article history: Received 1 May 2013 Received in revised form 3 October 2013 Accepted 28 October 2013 Available online 27 November 2013 Keywords: Soundscape Noise Perception Culture Urban Residential areas
a b s t r a c t This study examines the effects of cultural factors on the evaluation of acoustic quality of residential areas, within the context of general environmental conditions. A comparative study was carried out between the UK and Taiwan, through questionnaire surveys at three stages, namely in selected residential areas, with respondents in their place of work/study, and using a web-based survey, respectively. This study reveals the importance of considering cultural factors, as well as their living experiences. This is reflected by the significant differences between the two cultures in a number of aspects, including choosing and evaluating living environment, noise noticeability, annoyance and sleep disturbance, activities, and sound preference. It is interesting to note the factor ‘quiet’ is an important consideration compared to other factors, in both the UK and Taiwan. Crown Copyright © 2013 Published by Elsevier B.V. All rights reserved.
1. Introduction Globally, urban living has become increasingly widespread, seriously affecting urban sustainable development. Consequently, sound quality in our living environment is becoming ever more important, while the noise level is continuously increasing (Kuwano et al., 1999; Kang, 2006). In terms of sound quality, three factors should be considered: compatibility of the sounds, pleasantness of the sounds as well as identifiability of sounds (Guski, 1997). Social and demographic factors of the users may also play an important role in soundscape evaluation (Kang, 2006), as well as sound sensitivity of individuals (Zimmer and Ellermeier, 1999). Moreover, differences in urban texture, including building density, dimensions and boundaries of the areas can lead to different urban sound fields, which is an important consideration in assessing the sound environment (Kang, 2006).
In terms of urban acoustics sustainability, people's perception is an important factor (Yu, 2008). This is examined in this study through a comparative study in urban residential areas. Typical urban residential areas in the UK and Taiwan have been selected for comparison, considering differences in culture as well as urban texture. The main aim is to examine how people perceive their sound environment in the context of current situations of their living areas, and to identify the comfortable and pleasant sounds in terms of developing sustainable environments. This paper first introduces the survey methods at three stages. It then analyses the survey results in terms of choosing a living environment, effect of social and demographic factors when choosing a living environment, current living environment, environmental pollution, main activities, noise noticeability, annoyance, and sleep disturbance, and sound preference. 2. Methodology
⁎ Corresponding author. Tel.: +886 4 8876660. E-mail address: [email protected] (C.-J. Yu).
Two cities, Sheffield in the UK and Taipei in Taiwan, were selected for the comparative study. While the two cities are different in urban
0048-9697/$ – see front matter. Crown Copyright © 2013 Published by Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.scitotenv.2013.10.107
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Table 1 Situations of the case study sites, three in Sheffield, UK and three in Taipei, Taiwan.
Shef
Site
Land
House
Traffic/hour
Springvale Rd. Highton St. Cavendish St.
Sloped:1/12 Sloped:1/7 Sloped:1/20
Detached/terraced Detached/terraced Flat
57 54 84
texture, they both represent typical cities. The comparative study was carried out through a questionnaire survey at three stages. At stage one, on-site questionnaire surveys and interviews were made in six representative residential areas — three in Sheffield and three in Taipei. At stage two, a questionnaire survey was carried out in both Sheffield and Taipei with respondents in ten places of work/study in each city. At stage three, a web-based survey was carried out in both the UK and Taiwan. At stages one and two an identical questionnaire was used, which was designed to ascertain people's satisfaction with their living environment, including how they perceived environmental pollution and the quality of the ambient sound, and the identification of preferred sounds. The questionnaire at stage three had the same structure as that at stages one and two but fewer questions were included. At each stage, the questionnaire was in English in the UK and in Chinese in Taiwan and they were identical in context. A five-point linear scale was generally used in the questionnaire, for example, from −2, very uncomfortable, to 2, very comfortable. During the three stages of questionnaire survey, there were 80, 200 and 300 respondents, respectively. Over three stages, all respondents were selected at random, and the statistical analysis using software SPSS (2005) shows that the distribution of occupation, education, gender, and age was largely representative (Yu, 2008). In the analysis below, if the number of people in any group is fewer than 10, this group will be treated as missing data when comparing differences between groups. Table 1 shows the characteristics of the six residential areas at stage one, three in Sheffield and three in Taipei. The sites were selected to
Springvale Road
JianGuo S Road
Highton Street
GuoXing Road
TP
Site
Land
House
Traffic/hour
JianGuo S Rd. GuoXing Rd. ZhangXing E Rd.
Flat Flat Flat
Flat Flat Flat
8837 3861 7335
represent typical urban textures as well as residents' social, demographic and cultural backgrounds. Sound pressure level (SPL) measurements were made considering various typical time periods, and noise maps were made using software Cadna (2007). Whilst the traffic data and building heights used in the noise mapping were obtained through on-site observations and measurements, the calculation parameters in the noise maps were calibrated through comparisons between measured and calculated SPL. The noise maps of the six case study sites are shown in Fig. 1. 3. Results 3.1. Choosing a living environment Previous studies have shown that regional differences, including cultural heritage, construction methods, lifestyle and weather, may influence noise annoyance (Kang, 2006; Gjestland, 1998; Huang, 2004). The economic effects of community noise have also been examined, especially from the viewpoint of compensation payable on depreciation in property value. Such depreciations can be attributed to noise among other physical factors (Rosen, 1974; Walters, 1975; Nelson, 1982; Hufschmidt et al., 1983; Turner et al., 1994; Hawkins, 1999; Bateman et al., 2001; Navrud, 2002; Wardman and Bristow, 2004). Consequently, in this study, questions were asked about the importance of various factors when people choose a living environment. As mentioned above, a five-level linear scale was used, from −2, do not mind, to 2, very important. The results of stages one and two are shown in Fig. 2. Through
Cavendish Street, Sheffield
ZhangXing E Road, Taipei
Fig. 1. Plan of the case study sites in Sheffield and Taipei and corresponding noise-maps.
C.-J. Yu, J. Kang / Science of the Total Environment 482-483 (2014) 501–509
503
Fig. 2. Importance of various factors when choosing a living environment.
the Independent Samples Test, it can be seen that there are generally significant differences (p b 0.01) between the two cities for both stages one and two. It seems that respondents in Taipei gave considerably higher scores, by about 0.6 points on average, than the respondents in Sheffield, which might be a reflection of cultural differences, although in both cities the standard deviations (Std.) are relatively high compared to the mean value. In terms of the order of importance of various factors, from Fig. 2 it can be seen that there are similarities between the two cities in the first stage. For example, safety is at the top of both lists at both stages one and two. It is interesting to note that at stage one the factor ‘quiet’ is ranked as the 4th most important factor in Sheffield, and 3rd in Taipei, suggesting that in both cities, the sound environment is an important consideration compared to other factors. At stage two ‘quiet’ is ranked as the 6th important factor in Sheffield, and 4th in Taipei. The correlation coefficient between the two rankings is R2 = 0.57 at stages one and R2 = 0.46 at stage two. 3.2. Effect of social and demographic factors when choosing a living environment Social and demographic factors are important considerations when studying the subjective evaluation, although results of previous studies varied (Fields, 1993; Miedema and Vos, 1999; Rylander et al., 1972; Sato, 1993; Tonin, 1996; Yang and Kang, 2005a,b). Differences between
various education levels, age groups, current living environments, sleep quality, gender and occupations were examined in this study, and some results are shown in Table 2. It can be seen that for some factors including recreational space, sociable neighbourhoods, views, and more importantly for this study, quietness, there are significant effects from social and demographic factors, whereas in terms of convenience for work and interior decoration, the effects from social and demographic factors are generally insignificant. Between Sheffield and Taipei, it seems that the effects from social and demographic factors in the former were slightly higher. In terms of the effects of the above social and demographic factors on the evaluation of ‘quiet’ when choosing a living environment, Fig. 3 shows the results of stage two. In terms of occupation, as shown in Fig. 3e, in Sheffield there were significant differences between students, working people (people in employment) and pensioners (p b 0.01), with mean evaluation scores of 0.11, 0.83 and 1.58 respectively, whereas in Taipei such differences are not significant. In terms of current living environment, as shown in Fig. 3c, in Sheffield there is a slight trend that with a better current environment, people tend to think ‘quiet’ is more important, with a correlation coefficient of 0.166. In Taipei there is no such tendency. In terms of age, it is interesting to note in Fig. 3b that the age group 18–24 has a significantly lower score than that of the other groups (p b 0.000) in Sheffield, whereas in Taipei the differences between different age groups are not significant. The effects of education level and gender are generally not statistically significant, although
Table 2 Significance level of the correlations between occupation, education level, age, current living environment and choosing a living environment, where p b 0.01 are marked with ** and p b 0.05 marked with *. Sig. (2-tailed) Occupation
Stage 1 Stage 2
Education
Stage 1 Stage 2
Age
Stage 1 Stage 2
Current living
Stage 1 Stage 2
Shef TP Shef TP Shef TP Shef TP Shef TP Shef TP Shef TP Shef TP
Convenience for work
Convenience: transport
Convenience: school shopping
Recreational space
Sociable neighborhoods
Safety
Property price
Quiet
Views
Size of the house
Interior decoration
0.12 0.10 0.01** 0.46 0.80 0.98 0.59 0.86 0.39 0.19 0.27 0.44 0.15 0.91 0.01** 0.22
0.05 0.10 0.00** 0.36 0.10 0.98 0.01** 0.82 0.07 0.19 0.00** 0.24 0.56 0.91 0.54 0.17
0.91 0.14 0.21 0.16 0.04 0.67 0.00** 0.87 0.43 0.50 0.05* 0.94 0.64 0.04* 0.55 0.02*
0.00** 0.02* 0.00** 0.00** 0.00** 0.38 0.00** 0.23 0.01* 0.09 0.00** 0.07 0.88 0.07 0.79 0.03*
0.03* 0.46 0.00** 0.48 0.00** 0.01** 0.00** 0.16 0.09 0.47 0.01* 0.15 0.02* 0.11 0.00** 0.07
0.71 0.54 0.45 0.23 0.94 0.67 0.82 0.26 0.30 0.83 0.03* 0.78 0.06 0.39 0.00** 0.07
0.10 0.11 0.01** 0.86 0.13 0.71 0.02* 0.24 0.00** 0.43 0.00** 0.70 0.17 0.65 0.03* 0.46
0.02* 0.55 0.00** 0.19 0.13 0.91 0.01** 0.74 0.00** 0.52 0.00** 0.83 0.22 0.55 0.02* 0.60
0.02* 0.93 0.00** 0.12 0.44 0.17 0.16 0.05* 0.00** 0.67 0.00** 0.69 0.05 0.12 0.00** 0.13
0.24 0.95 0.05** 0.24 1.00 0.06 0.91 0.00** 0.00** 0.17 0.00** 0.45 0.17 0.01** 0.02* 0.03*
0.37 0.62 0.14 0.20 0.31 0.06 0.13 0.10 0.76 0.74 0.49 0.47 0.53 0.01* 0.41 0.01**
504
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a
b
2
2
Evaluation
-1
-2
-2 18
-1 7 11
U
ni ve
le v A
O
le v
el
rs ity
-1
-2 4 -3 4 35 -4 4 45 -5 4 55 -6 4 >6 5
0
25
0
el
Evaluation
1 1
Education
Age
c
d
2
Evaluation
1 0 -1 -2
1 0 -1
ye no
an y
er
er
V
V
er N
ei
th
d
ed
m
oy nn
A
M
ed
iu
d fie tis
y
V
sa
er
tis
y
fie
ba
d
d
d Ba
ba or
w
V
el
er
ln
y
w
W
el
l
el
l
d
-2 Sa
Evaluation
2
Living environment
e
Sleeping quality
f
2 1
Evaluation
1 0
0 -1
-1
al e Fe m
al
er s th O
W
St ud or en ki t ng pe rs on Pe ns io ne H ou r se ke ep er
e
-2
-2
M
Evaluation
2
Occupation
Gender
Fig. 3. Effects of social and demographic factors when choosing a living environment, in terms of ‘quietness’, based on the results of stage two. Black bars: UK; white bars: Taipei.
there are some differences in the mean evaluation scores, as shown in Fig. 3a and f, respectively. It is somewhat unexpected that the correlation between sleep quality and choosing a quiet environment is not high, as can be seen in Fig. 3d. 3.3. Current living environment Table 3 compares the perception of respondents in Sheffield and Taipei of their general living environment, sound quality of their living area, and sound quality at home, where five-point linear scales were again used, from 1, comfortable, to 5, very uncomfortable. The results of stage one, two and three all show that the scores in Taipei are significantly higher than those in Sheffield, by about 0.5–0.7, indicating that the general living condition/environment and the acoustic environments in Taipei are less comfortable in terms of people's perception.
For sound environment, it is interesting to note that this corresponds to the noise level difference between the two cities, as shown in Fig. 1, which is about 10 dBA. In Table 3 the evaluation of general health level is also examined based on results at stages one and two. The results correspond to the evaluation of their living environment and sound quality. Taipei residents also found their health condition less satisfactory compared to that in Sheffield, with a difference of 0.79 in the mean evaluation score at stage one and 0.72 at stage two. 3.4. Environmental pollution Whilst the importance of sound quality and quietness has been demonstrated above, in the questionnaire the respondents were asked to rank the four pollutions, namely water, air, noise and waste. The
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Table 3 Evaluations of living environment and sound quality of the living area and home. Stage 1
General living environment Sound quality of living area Sound quality of home Health
Mean Std. Mean Std. Mean Std. Mean Std.
Stage 2
Shef
TP
Shef
TP
UK
TW
1.81 0.53 2.16 0.65 1.95 0.53 1.75 0.83
2.43 0.9 2.44 0.93 2.59 0.88 2.54 0.75
1.82 0.53 1.79 0.86 2.13 0.6 1.97 0.53
2.36 0.87 2.49 0.78 2.65 0.96 2.69 0.89
2.26 0.71 2.23 0.88 2.25 0.93
2.65 0.79 2.95 0.88 2.74 0.75
stage one and two results are shown in Table 4. For example, the mean ranking order at stage one is: air, 2.09; noise, 2.12; waste, 2.53; water, 3.26, in Sheffield, and air, 2.29; noise, 2.33; water, 2.81; waste, 2.94, in Taipei. It is important to note that at stage one, both Sheffield and Taipei noise were perceived as the second serious pollutant, with a slightly lower score than air pollution, and at stage two, noise is even perceived as the first serious pollutant in Sheffield. The importance of noise pollution in the overall sustainable urban environment has also been demonstrated by other researchers (Peyton, 2005; Cowell, 2005). 3.5. Main activities Since noise may be more disturbing for certain activities, such as oral communication, listening to radio and intellectual tasks, than for other activities, the main activities of the respondents when they stay at home were asked about, and in the questionnaire multiple choices were allowed. The results of three stages are shown in Table 5. It can be seen that in both cities there was a high percentage of activities which could potentially be disturbed by noise. It seems that there were high percentages of reading and music in Sheffield than those in Taipei, suggesting that Sheffield people could be more sensitive in terms of disturbance of activities. Between stage one and stage two there is an insignificant difference in both cities. 3.6. Noise sources: noticeability, annoyance, and sleep disturbance Noise annoyance may increase if a neighbourhood is perceived in a negative way, and it is also influenced by the life-style chosen by certain people, for whom a certain quantity of noise is part of their life. Moreover, people may get used to certain noises and thus become less annoyed (Kang, 2006). Consequently, various sources in an urban soundscape could have different impacts on people, and this could vary with different cultural environments. In the questionnaire the noticeability, annoyance level and sleep disturbance of typical sound sources in residential areas were examined, where five-point linear scales were again used.
Table 4 Ranking of various types of environmental pollution. Stage 1
Water pollution
Air pollution
Noise pollution
Waste pollution
Mean rank Std. Rank Mean rank Std. Rank order Mean Std. Rank Mean rank Std. Rank
Stage 3
Stage 2
Shef
TP
Sig.
Shef
TP
Sig.
3.26 0.96 4 2.09 0.90 1 2.12 1.20 2 2.53 1.02 3
2.81 1.30 3 2.29 1.01 1 2.33 1.12 2 2.94 1.34 4
0.12
3.06 1.13 4 1.96 0.91 2 1.81 1.12 1 2.20 1.09 3
2.49 1.25 3 1.92 0.97 1 2.08 1.08 2 3.07 1.18 4
0.00
0.95
0.49
0.01
0.78
Difference between Stage 1 & 2 (%)
Difference between Stage 2 & 3 (%)
Shef
TP
Shef-UK
TP-TW
0.50
−3.00
19.47
10.94
−21.00
2.01
19.73
15.59
8.45
2.26
5.33
3.28
In terms of noticeability, the results of stages one and two are shown in Fig. 4. It can be seen that there are generally considerable differences between Sheffield and Taipei, with Taipei having significantly greater scores, namely easier to be noticed. This reflects the difference in noise levels in the two cities. The SPL in the Taipei sites were about 10 dBA higher than those in Sheffield at typical roadside receivers, due to the difference in landform, building types, and more importantly, traffic density. Between the three sites in Sheffield the SPL varied by about 6 dBA, and the variation range in Taipei was similar. Interestingly, in terms of ranking of various noise sources, people living in Sheffield had a greater score in terms of noticeability on traffic noise, especially heavy vehicles, although their SPL was actually much lower than that in Taipei. In Taipei, the noise sources at the top list were two wheelers (i.e. motorcycles), as well as talking, music and TV, from neighbours. According to Guski (1998), the noise annoyance by inhabitants only depends on approximately 33% of the acoustic parameters such as acoustic energy, number of sound events, and length of moments of calm between intermittent noises. The annoyance level and sleep disturbance of stages one and two are shown in Figs. 5 and 6, respectively. It can be seen that the annoyance level generally corresponds to the noticeability level, and the evaluation of sleep disturbance also corresponds to noticeability and annoyance level. In terms of annoyance, traffic noise again ranked highest in Sheffield, whereas in Taipei two wheelers and talking/music/TV were found most annoying, as well as the annoyance caused by nearby events. In terms of sleep disturbance, traffic noise is also at the top of the list in Sheffield, namely was considered most annoying, as well as talking/music/TV, from neighbours, whereas in Taipei two wheelers and talking/music/TV are found most disturbing, as well as heavy vehicles. The evaluation of sleep disturbance generally corresponds to that for noticeability and annoyance. The correlations between noticeability, annoyance and sleep disturbance of stage two are further demonstrated in Figs. 7 and 8, based on the results at stage two. It can be seen that the correlations are high, ranging from 0.72 to 0.95. In both stages one and two, it is particularly interesting to note that the noticeability scores are generally systematically higher than those of annoyance scores, which suggests that although people may notice many sounds, they are not necessarily annoyed, showing people's tolerance. In urban open public spaces similar results are also found (Kang, 2006).
Table 5 Main activities at home (%), where multiple choices were allowed. Stage 1
0.05
0.00
Stage 2
Activities
Shef
TP
Shef
TP
Reading TV Music Others
61 54 55 41
35 85 9 29
63 57 57 45
38 81 5 29
Stage 1 - Sheffield
Stage 1 - Taipei
Nearby events
Stage 2 - Sheffield
Fig. 6. Sleep disturbance of various noise sources in Sheffield and Taipei.
Stage 2 - Sheffield
Self- house air-conditioning
Self- house air-conditioning
Self- house talking, music, TV
Neighbours air-conditioning
Stage 2 - Sheffield
Self- house talking, music, TV
Nearby events Neighbours talking, music, TV
Factors
Neighbours air-conditioning
Stage 1 - Taipei Nearby transportation stations
Stage 1 - Taipei
Nearby transportation stations
Nearby recreation
Nearby shops
Nearby recreation
Nearby shops
Nearby school
Motorbike
Heavy vehicle
Medium vehicle
Light vehicle
Self- house air-conditioning
Self- house talking, music, TV
Neighbours air-conditioning
Neighbours talking, music, TV
Nearby events
Nearby transportation stations
Factors
Neighbours talking, music, TV
Factors
Nearby recreation
Nearby shops
Stage 1 - Sheffield Nearby school
Motorbike
Heavy vehicle
Medium vehicle
Light vehicle
Mean Stage 1 - Sheffield
Nearby school
Motorbike
Heavy vehicle
Medium vehicle
Light vehicle
Mean
Mean
506 C.-J. Yu, J. Kang / Science of the Total Environment 482-483 (2014) 501–509
2 1.5 1 0.5 0 -0.5 -1 -1.5 -2
Stage 2 - Taipei
Fig. 4. Noticeability of various noise sources in Sheffield and Taipei.
2 1.5 1 0.5 0 -0.5 -1 -1.5 -2
Stage 2 - Taipei
Fig. 5. Annoyance of various noise sources in Sheffield and Taipei.
2 1.5 1 0.5 0 -0.5 -1 -1.5 -2
Stage 2 - Taipei
C.-J. Yu, J. Kang / Science of the Total Environment 482-483 (2014) 501–509
a 2
2
1
1
0
Annoyance
Annoyance
a
507
2
R = 0.882
-1
2
R = 0.9545
0 -1
-2 -2
-1
0
1
-2
2
-1
0
Noticeability
b
b Sleep disturbance
Sleep disturbance
2 1 0 R2 = 0.7244
-1 -2
-2
-1
0
1
Sleep disturbance
Sleep disturbance
2 1 0 R2 = 0.9251
-1
1
2
-1
0
2 1
1
2
R = 0.9358
0 -1 -2
0
2
2
R = 0.9139
0
Noticeability
c
-1
1
1
-2 -1
2
c
-2
2
2
Noticeability
-2
1
Noticeability
-1
0
2
Annoyance
Annoyance Fig. 7. Relationships between noise noticeability, annoyance and sleep disturbance in Sheffield, based on the results at stage two.
3.7. Sound preference Urban soundscape includes not only negative, but also positive sounds. Given the effects of various sound sources shown above, and it has been previously demonstrated that positive sounds could improve urban soundscape without necessarily reducing the level of noise sources (Kang, 2006), sound preference was studied through the questionnaire survey, where the respondents were asked to select the sounds they prefer from a list. The results are shown in Table 6, where differences between Sheffield and Taipei are also examined statistically and the significance levels are shown. It is interesting to note that there are generally significant differences in sound preference between Sheffield and Taipei. At stages one and two, the preference level of bird sounds and water sounds is much higher in Sheffield than in Taipei, by 38%, 42% and 20%, 20%, respectively. On the other hand, in Sheffield insect sounds and music from outside were almost not selected, whereas this percentage is 20–25% in Taipei. There are also a higher percentage of people in Sheffield who suggested other preferred sounds.
Fig. 8. Relationships between noise noticeability, annoyance and sleep disturbance in Taipei, based on the results at stage two.
In the stage three study, respondents were asked to select the sounds they would prefer, both in the living area and at home, from a given list, including both natural sounds and artificial sounds. Table 7
Table 6 Preference of various sounds, with 1 as yes (selected) and 2 as no, based on results at stages one and two. Stage 1
Birdsong Insect sounds Water Music from outside Other sounds
Mean Std. Mean Std. Mean Std. Mean Std. Mean Std.
Stage 2
Shef
TP
Sig.
Shef
TP
Sig.
1.3 0.46 1.96 0.19 1.69 0.47 1.96 0.19 1.71 0.46
1.68 0.48 1.79 0.42 1.89 0.32 1.74 0.45 1.89 0.57
0.8
1.28 0.45 1.97 0.18 1.73 0.45 1.96 0.21 1.71 0.45
1.7 0.88 1.93 0.8 1.93 0.96 1.65 0.89 1.94 0.65
0.00**
0.00** 0.00** 0.00** 0.61
0.49 0.01* 0.00** 0.00**
508
C.-J. Yu, J. Kang / Science of the Total Environment 482-483 (2014) 501–509
Table 7 Preference of various natural sounds and artificial sounds, with 1 as yes (selected) and 2 as no, based on results at stage three. Area
Natural sounds
Bird songs Water Insect sounds Quiet Others
Artificial sounds
Bells of church Music Traffic sound Others
Mean Std. Mean Std. Mean Std. Mean Std. Mean Std. Mean Std. Mean Std. Mean Std. Mean Std.
Home
UK
Rank
TW
Rank
Sig.
UK
Rank
TW
Rank
Sig.
1.59 0.49 1.71 0.45 1.95 0.23 1.51 0.50 1.97 0.17 1.77 0.42 1.52 0.5 1.95 0.22 1.98 0.13
2
1.49 0.50 1.83 0.37 1.71 0.45 1.41 0.49 2.00 0.00 1.95 0.22 1.83 0.37 1.98 0.14 2.00 0.00
2
0.00**
2
0.00**
0.00**
4
0.00**
3
0.00**
3
0.00**
1
0.00**
1
0.04*
5
0.00**
5
0.00**
2
0.00**
2
0.00**
1
0.00**
1
0.00**
3
0.00**
3
0.25
4
0.00**
1.69 0.46 1.91 0.29 1.78 0.42 1.40 0.49 2.00 0.00 1.99 0.08 1.41 0.49 2.00 0.06 2.00 0.00
2
4
1.76 0.43 1.78 0.41 1.98 0.15 1.44 0.50 1.97 0.16 1.93 0.26 1.31 0.46 1.99 0.08 1.97 0.18
3
0.00**
3 4 1 5 2 1 3 4
shows the results. Through the Independent Samples Test, it can be seen that there are significant differences between the UK and Taiwan for nearly all sounds listed. However, it is interesting to note that in terms of the ranking of sound preference, the differences between the UK and Taiwan are generally insignificant. The correlations between the UK and Taiwan rankings are relatively high, with R2 = 0.5–1. In both the UK and Taiwan, ‘quiet’ is highly preferred both in the living area and at home. This is followed by bird songs and water sounds, although it is interesting to note that these two sounds were less preferred at home compared to the living area, both in the UK and Taiwan. Insect sounds were less preferred in the UK compared to Taiwan, which was similar to the results obtained at stages one and two. Church bells were less preferred in Taiwan compared to the UK, likely caused by cultural differences. Music was generally preferred both in the living area and at home, although the preference level is higher at home. It is interesting that the preference level of music was higher in the UK than that in Taiwan, which corresponds to people's activities, as shown in Table 7. As expected, traffic sounds are generally the least preferred (Kang, 2006). Moreover, it is important to note that the standard deviation for traffic sounds is much less than that for other more preferred sounds. 4. Conclusions The survey results at the three stages show that people's perceptions of their living environment can be affected by different cultural and social factors, as well as their living experiences. In terms of choosing a living environment, it is interesting to note the factor ‘quiet’ is an important consideration compared to other factors. The general living condition/environment and the acoustic environments in Taipei are less comfortable in terms of people's perception, by about 0.5–0.7 in terms of evaluation score at a five-point scale. Besides, Taipei residents also found their health condition less satisfactory compared to residents in Sheffield. In terms of environmental pollution, in both Sheffield and Taipei noise was perceived as a serious pollutant. In both cities there was a high percentage of activities which could potentially be disturbed by noise, and those in Sheffield could be more sensitive in terms of disturbance of activities. In terms of noise noticeability, there are generally considerable differences between Sheffield and Taipei, with Taipei having higher noticeability of noise sources. Among noise annoyance, noticeability and sleep disturbance there are high correlations, and the noticeability level is generally systematically higher than that of annoyance level,
3 5 1 4 2 1 4 3
showing people's tolerance. In terms of annoyance of different noise sources, and also sound preference, there are generally significant differences between Sheffield and Taipei, and between the UK and Taiwan. This study suggests the great importance of considering the cultural differences in noise policies as well as noise abatements measures. With a holistic framework, for example, based on the WHO guidelines (Berglund et al., 1999), different countries/regions could have specific regulations and abatement measures for specific noise sources. It is also important to take the principles of soundscape approaches into account (Kang, 2006), by designing the balance of difference source sources, rather than only reducing noise levels. References Bateman IJ, Day B, Lake I, Lovett AA. The effect of road traffic on residential property values: a literature review and hedonic pricing study. Edinburgh: Report commissioned by the Scottish Executive Development Department; 2001. Berglund B, Lindvall T, Schwela DH. Guidelines for community noise. World Health Organization report; 1999. DataKustik GmbH. Cadna/A for Windows – UserManual.Munich, Germany; 2007. Cowell JR. Sustainable design in acoustics. Proceedings of the Institute of Acoustics; 2005. Fields JM. Effect of personal and situational variables on noise annoyance in residential areas. J Acoust Soc Am 1993;93:2753–63. Gjestland T. Regional differences in noise annoyance assessments. Proceedings of inter-noise; 1998. Guski R. Psychological methods for evaluating sound quality and assessing acoustic information. Acustica united with acta acustica, 83; 1997765–74. Guski R. Psychological determinants of train noise annoyance. Proceedings of euro-noise; 1998. Hawkins R. Review of studies on external costs of noise. Environmental Protection Economics Division of the (former) UK Department for Environment, Transport and the Regions (DETR); 1999. Huang Z. Environmental noise situation of residential areas and the change with city expansion in Xi'an City, China. (MArch dissertation). UK: University of Sheffield, School of Architecture; 2004. Hufschmidt MM, James DE, Meister AS, Browen BT, Dixon JA. Environment, natural systems, and development: an economic valuation guide. Baltimore: John Hopkins University Press; 1983. Kang J. Urban Sound Environment. London: Taylor & Francis incorporating Spon; 2006. Kuwano S, Namba S, Florentine M, Zheng DR, Fastl H, Schick A. A cross-cultural study of the factors of sound quality of environmental noise. Presented at the 137th Meeting of the Acoustical Society of America and Forum Acusticum, Berlin, 105. Abstract published in Journal of Acoustical Society of America; 1999. p. 1081. Miedema HME, Vos H. Demographic and attitudinal factors that modify annoyance from transportation noise. J Acoust Soc Am 1999;105:3336–44. Navrud S. The state-of-the-art on economic valuation of noise. Final Report to European Commission Directorate-General (DG) Environment; 2002. Nelson JP. Highway noise and property values: a survey of recent evidence. J Transp Econ Policy 1982;16:117–38. Peyton CH. Creating through sustainable design. Proceedings of the Institute of Acoustics; 2005.
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