BRAlN
AND
LANGUAGE
4,
153-161 (1991)
Speech Discrimination and Lip Reading in Patients with Word Deafness or Auditory Agnosia MITSUKO SHINDO, KIMITAKA
KAGA, AND YOSHISATO TANAKA
Department of Otolaryngology, Teikyo University Tokyo, Japan
School
of Medicine,
The purpose of this study was to assess the ability of four patients with word deafness or auditory agnosia to discriminate speech by reading lips. The patients were studied using nonsense monosyllables to test for speech discrimination, a lip reading test, the Token Test for auditory comprehension, and the Aphasia test. Our results show that patients with word deafness or auditory agnosia without aphasia can improve speech comprehension by reading lips in combination with listening, as compared with lip reading or listening alone. In conclusion, lip reading Q IWI was shown to be useful for speech comprehension among these patients. Academic
Press. Inc.
I. INTRODUCTION It has been noted that patients with word deafness or auditory agnosia after cerebrovascular accidents often utilize lip reading to understand the conversation of others (Tanaka, Taguchi, Sakabe, & Igarashi, 1964; Michel & Peronnet, 1980; Stockert, 1982; Auerbach, Allard, Naeser, Alexander, & Albert, 1982; Marshall, Rappaport, & Garcia-Bunuel, 1985). For people with normal hearing, lip reading often provides useful cues in speech perception, but is not generally a crucial source of speech information (Dodd, 1987). For patients with word deafness or auditory agnosia, however, lip reading is the primary sauce of speech information. The purpose of the present study was to investigate the lip reading abilities of patients with word deafness or auditory agnosia. Address correspondence and reprint requests to Mitsuko Shindo, Department of Otolaryngology, Teiko University School of Medicine, 2-11-1, Kaga, Itabashi-ku, Tokyo 173, Japan. 153 0093-934W91 $3.00 Copyright 0 IYYl by Academic Press. Inc. All rights of reproduction m any form reserved.
154
SHINDO, KAGA, AND TANAKA
II. METHODS
1. Subjects One patient with word deafness and three patients with auditory agnosia were studied. All were right-handed, and in all cases the cerebrovascular lesions involved at least the unilateral auditory cortex, or bilateral auditory cortices. The auditory brain stem responses (ABR) were normal in all patients. Conversational speech in these patients was fluent, with no paraphasia or confrontation naming observed. Reading aloud and reading comprehension in the patients were good to fully normal in the Standard Language Test of Aphasia in Japan. A profile of the patients is listed in Table 1.
2. Methods Three neuropsychological tests were used to assessthe auditory perception, comprehension, and lip reading ability of the patients. Each was tested at least 6 months after his or her cerebrovascular accident. (1) Speech discrimination test for auditory perception. Fifty-three Japanese nonsense monosyllables in a speech discrimination test devised by the authors (Tanaka, Shindo, & Kaga, 1981) were used. These 53 nonsense monosyllables for auditory perception are the most complex of 100 monosyllables that exist in the Japanese language, as determined by language science. The sounds in the test were tape-recorded and delivered to each ear separately through headphones at an intensity of 50 dB above the subjective threshold. Each patient was asked to respond orally or in writing. (2) Token Test for auditory comprehension. This test, devised by De Renzi and Vignolo (1962), was used to determine the degree of impairment of auditory comprehension. Each patient was tested using oral speech sounds with the examiner’s mouth concealed from the patient’s view. (3) Lip reading test. Lip reading tests composed of Japanese words of three syllables and short sentences, devised by Tanaka and Chiba (1975), were used (Table 2). The words in this test were selected for their high degree of difficulty in terms of auditory and/or visual discrimination (e.g., “usagi,” which means rabbit, and “unagi,” meaning eel, have the same mouth shape but sound different). The short sentences, of three to five syllables, were selected from reading ability tests for lower grade elementary school children (e.g., “Makotosanwa doubutsuen-e ikimashita,” meaning “Makoto went to a zoo”). These tests were performed three times in the following order: (1) lip reading only, (2) listening only, and (3) a combination of lip reading plus listening.
III. RESULTS
1. Controls (1) In normal subjects, the 53 nonsense monosyllables were identified correctly at a percentage rate of 84 2 7% (the average age was 29.5 years old; n = 20). No right ear/left ear differences were found. (2) In the Token Test, the percentage of correct responses in normal subjects was 98 + 3% (the average age was 44.9 years old; n = 54) (Hosokawa, Hosokawa, Rynichi, et al., 1981). (3) In the lip reading test, the percentage correct was only 17 * 7% for words and 40 + 17% for short sentences. The percentage correct in the listening only test was lOO%, and that for lip reading plus listening was also 100% (the average age was 27.5 years old; n = 23) (Tanaka, Chiba, 1975).
SPEECH DISCRIMINATION
155
AND LIP READING
TABLE 1 THE PATIENTS
LIST OF
Case Age 1 2 3 4
24 53 65 55
F F M M
Lesion
Cause
Sex
L, R: Auditory radiation Moyamoya disease Subarachnoidal hemorrhage L, R: T, L, R: T, Cerebral infarction L : T, Cerebral bleeding
Diagnosis Auditory agnosia Auditory agnosia Auditory agnosia Word deafness
TABLE 2 THE LIP READING
1. Usagi [rabbit] 2. Unagi [eel]
TESTS
A. Three-syllable Japanese words 3. Hashiru [run] 4. Ahiru [duck]
5. Hanashi [talk] 6. Hadashi [bare feet]
9. Byoin [hospital] 10. Byonin [patient]
11. Daikon [radish] 12. Raion [lion]
13. Tenki [weather] 14. Denki [electricity] 15. Genki [vigor]
16. Uwagi [coat] 17. Uwaki [fickleness]
18. Ikari [anger] 19. Hikari [light]
20. Garasu [glass]
22. Tabako [tobacco] 23. Tamago [egg]
24. Yasai [vegetables] 25. Yasashii [gentle]
7. Hanaji [nose bleed] 8. Katachi [shape]
21. Karasu [crow]
B. Japanese short sentences 1. Makotosanwa dobutsuen-e ikimashita. [Makoto-San went to a zoo.] 2. Kazega soyosoyoto fuite imasu. [The wind blows gently.] 3. Tokukara densyaga hashitte kimashita. [A tram has come from far away.] 4. Kyowa otosanno tanjobi desu. [Today is my father’s birthday.] 5. Ojiisanga yamamichio tobotoboto nobotte ikimasu. [An old man is going up a mountain path slowly.] 6. Ieno urani ogawaga nagarete imasu. [There is a stream behind a house.] 7. Kochirawa mainichi yukiga futte imasu. [It snows every day here.] 8. Okina namiga donto yosete kimasu. [A big wave breaks with a thud.] 9. Kosakuno jikanni mizudeppo-o tsukurimashita. [I made water pistols in the handicraft class.] 10. Koenwa furui oshirono atoni arimasu. [There is a park on the ruins of an old castle.]
156
SHINDO, KAGA, AND TANAKA
Discrimination
of mmosyl .lables
L:
2%
R:
2%
Tdetl Test : 22 x
;g,::, Lfi osy;n li,re$i,lg ‘i”‘g$” lip r~admg + Ilsleninp
lip~nreinc
Ihaten;g
I(p ryadw + llltenicq
FIG. 1. Results of case 1. (A) Illustration of the lesion sites demonstrated by CT scan. (B) Audiogram. (C) Discrimination of 53 Japanese nonsense monosyllables: L, left ear; R, right ear. Token Test. (D) Lip reading tests.
2. Case Report
In case 1 (Fig. l), a 24-year-old woman with moyamoya disease, the lesion was shown by CT scan to be located bilaterally in the auditory radiations. Pure tone audiometry showed normal hearing threshold. Monosyllable tests in both ears (with scores of 2% in each case) and the Token Test (a score of 22%) indicated severe impairment. In the lip reading tests, the score for lip reading plus listening for words was 48%, which was markedly better than those for lip reading only (12%) or for listening only (0%). For short sentences, the score for lip reading plus listening (20%) was a little better than those for lip reading only (0%) or for listening only (10%). In case 2 (Fig. 2), a 53-year-old woman with subarachnoidal hemorrhage, the lesion was located in the left auditory radiation and right T,. Pure tone audiometry showed an apparent sensory hearing deficit, but ABR was normal. The monosyllable test scores in both ears was 0%. On the other hand, the Token Test score was 57%. The score for lip reading plus listening for words was 68%, which was better than those for lip reading only (40%) or for listening only (24%). For short sentences, the score for lip reading plus listening (80%) was remarkably better than those for lip reading only (10%) or for listening only (10%).
SPEECH DISCRIMINATION
AND LIP READING
157
Case 2
D
Lip ReZIing Words
80
sentences
70 60 ‘50 30 20 10
40 1 FIG. 2. Results of case 2. (A) Illustration of the lesion sites demonstrated by CT scan. (B) Audiogram. (C) Discrimination of 53 Japanese nonsense monosyllables: L, left ear; R, right ear. Token Test. (D) Lip reading tests.
In case 3 (Fig. 3), a 65-year-old man with cerebral infarction, the lesion was bilaterally located in T,. Pure tone audiometry showed near normal hearing. The monosyllable test scores were only 8% in the right ear and 15% in the left ear. On the other hand, the Token Test score was 62%. The score for lip reading plus listening for words was 36%, which was better than those for lip reading only (0%) or for listening only (24%). For short sentences, the score for lip reading plus listening (20%) was a little better than those for lip reading only (0%) or for listening only (0%). In case 4 (Fig. 4), a 55year-old man with cerebral bleeding, the lesion was located in the left T,. Pure tone audiometry showed normal hearing. The monosyllable test scores were only 2% in both ears; the Token Test score was 51%. The score for lip reading plus listening for words was 68%, which was markedly better than those for lip reading only (0%) or for listening only (36%). In the test for short sentence lip reading showed a similar result: the score for lip reading plus listening (60%) was markedly better than those for lip reading only (0%) or for listening only (10%).
158
SHINDO, KAGA, AND TANAKA
Case 3
Discrimination
of mnosvll&les
L : 15% R:
8%
Taken Test : 62 %
HI
Lip Reading
FIG. 3. Results of case 3. (A) Illustration of the lesion sites demonstrated by CT scan. (B) Audiogram. (C) Discrimination of 53 Japanese nonsense monosyllables: L, left ear; R, right ear. Token Test. (D) Lip reading tests.
IV. DISCUSSION The present study demonstrated that among these patients, auditory comprehension improved when lip reading was combined with listening, as compared to lip reading alone or listening alone. 1. Speech Discrimination
and Lip Reading Ability
Ikemura (1983) reported that although hearing acuity among patients with word deafness or auditory agnosia was normal or mildly defective, the speech discrimination score ranged from O-40%, 50% in each ear. In the present study, the speech discrimination score using 53 nonsense monosyllables was 2-B% in these four patients. The auditory comprehension score of words or short sentences on the Token Test, however, was 22-62%. Similar results have been reported in other studies, indicating that patients with word deafness or auditory agnosia are unable either to listen to or to repeat nonsense syllables (Stockert, 1982) and nonsense words (Metz-Lutz & Dahl, 1984), as opposed to meaningful words and sentences. It is important, accordingly, that patients with word deafness or auditory agnosia are able to listen to some extent to speech consisting of meaningful words and sentences.
SPEECH DISCRIMINATION
AND LIP READING
159
Ib Lip
Reading
FIG. 4. Results of case 4. (A) Illustration of the lesion sites demonstrated by MRI. (B) Audiogram. (C) Discrimination of 53 Japanese nonsense monosyllables: L, left ear; R, right ear. Token Test. (D) Lip reading tests.
2. The Effect of Lip Reading on Auditory
Comprehension
Among the four patients in this study, three used lip reading in their daily lives as a means of communication. In the case of simple conversation, they could understand family members or acquaintances by reading their lips. For more complicated conversation, however, they relied on written communication. It has been reported that among patients with word deafness or auditory agnosia, lip reading is commonly used to help understand ordinary conversation (Tanaka et al., 1964; Michel et al., 1980; Stockert, 1982; Auerbath et al., 1982; Marshall et al., 1985). It is further reported that such patients usually understand only simple words by lip reading (Metz-Lutz et al., 1984) and rely on writing in most conversations (Tanaka et al., 1964; Leicester, 1980; Shindo, Kaga, & Tanaka, 1981). In this study, the lip-reading-only scores in these patients were lower than those among controls in tests of both words and short sentences. The scores for lip reading combined with listening, however, were better than those for lip reading only or listening only in tests of both words and short sentences. Auerbach et al. (1982) reported that by combining
160
SHINDO, KAGA, AND TANAKA
listening with lip reading, auditory comprehension could be improved in patients with pure word deafness. Erber (1969) reported that the score of listening to spoken spondaic words was higher with listening plus lip reading than with listening only among normal subjects. Furthermore, Sanders and Goodrich (1971) reported that the listening score of frequency distortion sounds of phonetically balanced words was better with listening plus lip reading than with listening only, being statistically significant at the 0.01 level among normal subjects. Therefore, comprehension of speech sounds may possibly be improved if residual hearing acuity is combined with lip reading, not only in patients with peripheral hearing disorders but also in those with word deafness or auditory agnosia. Experimental investigation of the lip reading abilities of adults with normal hearing has demonstrated that in ordinary speech, they use visual cues from lip reading about 25% of the time (Dodd, 1977). It is now well established that adults with normal hearing use lip-read cues to augment their perception of speech. Therefore, lip reading helps in the perception of speech, and this ability appears to remain preserved in patients with word deafness or auditory agnosia. In conclusion, it is emphasized that patients with word deafness, or with auditory agnosia without aphasia, may use lip reading to improve their comprehension of speech. REFERENCES Auerbach, S. H., Allard, T., Naeser, M., Alexander, M. P., & Albert, M. L. 1982. Pure word deafness-Analysis of a case with bilateral lesions and a defect at the prephonemic level. Bruin, 105, 271-300. Campbell, R., Landis, T., & Regard, M. 1986. Face recognition and lipreading-A neurological dissociation. Bruin, 109, 509-521. De Renzi, E., & Vignolo, L. A. 1962. The Token Test: A sensitive test to detect receptive disturbances in aphasics. Brain, 85, 665-678. Dodd, B. 1977. The role of vision in the perception of speech. Perception, 6, 31-40. Dodd, B. 1987. Lip-reading, phonological coding and deafness. In B. Dodd & R. Campbell (Eds.), Hearing by eye: The psychology of lip-reading. London: Lawrence Erlbaum Associates. Pp. 177-189. Erber, N. P. 1969. Interaction of audition and vision in the recognition of oral speech stimuli. Journal of Speech and Hearing Research, 12, 423-425. Hosokawa, T., Hosokawa, K., Rynichi, N., et al. 1981. The Token Test in preschool and adult aphasics. In C. C. Peng (Ed.), Current issues in neurolinguistics: A Japanese contribution. Tokyo: The ICU Language Sciences Summer Institute. Pp. 69-95. Ikemura, Y. 1983. The development of the study of pure word deafness. Psychiatry, 25, 351-361. Leicester, J. 1980. Central deafness and subcortical motor aphasia. Bruin and Language, 10, 224-242. Marshall, R. C., Rappaport, B. Z., & Garcia-Bunuel, L. 1985. Self-monitoring behavior in a case of severe auditory agnosia with aphasia. Brain and Language, 24, 297-313. Metz-Lutz, M., & Dahl, E. 1984. Analysis of word comprehension in a case of pure word deafness. Brain and Language, 23, 13-25.
SPEECH DISCRIMINATION
AND LIP READING
161
Michel, F.. & Peronnet, F. 1980. A case of cortical deafness: Clinical and electrophysiological data. Brain and Language, 10, 361-317. Sanders, D. A., and Goodrich, S. J. 1971. The relative contribution of visual and auditory components of speech to speech intelligibility as a function of three conditons of frequency distortion. Journal of Speech and Hearing Research, 14, 154-159. Shindo. M., Kaga, K., & Tanaka. Y. 1981. Auditory agnosia following after bilateral temporal lobe lesion-Report of a case. Brain and Nerve, 33, 139-147. Stockert. T. R. 1982. On the structure of word deafness and mechanisms underlying the fluctuation of disturbances of higher cortical functions. Brain and Language, 16, 133146. Tanaka, Y., & Chiba F. 1975. Speechreading test using a video tape recorder and its application to hearing aid evaluation. Audiology Japan, 18, 195-202. Tanaka, Y., Shindo, M., & Kaga, K. 1981. Clinical tests of central auditory dysfunction. F. Ota (Ed.), Brain and auditory dysfunction. Tokyo: Shinohara Publisher. Pp. 655 102. Tanaka, Y., Taguchi, K., Sakabe, N., & Igarashi, E. 1964. Pure auditory agnosia associated with alteration of voice and personal character, Folia fhoniatrica, 17, 185-194.
AND
LANGUAGE
4,
153-161 (1991)
Speech Discrimination and Lip Reading in Patients with Word Deafness or Auditory Agnosia MITSUKO SHINDO, KIMITAKA
KAGA, AND YOSHISATO TANAKA
Department of Otolaryngology, Teikyo University Tokyo, Japan
School
of Medicine,
The purpose of this study was to assess the ability of four patients with word deafness or auditory agnosia to discriminate speech by reading lips. The patients were studied using nonsense monosyllables to test for speech discrimination, a lip reading test, the Token Test for auditory comprehension, and the Aphasia test. Our results show that patients with word deafness or auditory agnosia without aphasia can improve speech comprehension by reading lips in combination with listening, as compared with lip reading or listening alone. In conclusion, lip reading Q IWI was shown to be useful for speech comprehension among these patients. Academic
Press. Inc.
I. INTRODUCTION It has been noted that patients with word deafness or auditory agnosia after cerebrovascular accidents often utilize lip reading to understand the conversation of others (Tanaka, Taguchi, Sakabe, & Igarashi, 1964; Michel & Peronnet, 1980; Stockert, 1982; Auerbach, Allard, Naeser, Alexander, & Albert, 1982; Marshall, Rappaport, & Garcia-Bunuel, 1985). For people with normal hearing, lip reading often provides useful cues in speech perception, but is not generally a crucial source of speech information (Dodd, 1987). For patients with word deafness or auditory agnosia, however, lip reading is the primary sauce of speech information. The purpose of the present study was to investigate the lip reading abilities of patients with word deafness or auditory agnosia. Address correspondence and reprint requests to Mitsuko Shindo, Department of Otolaryngology, Teiko University School of Medicine, 2-11-1, Kaga, Itabashi-ku, Tokyo 173, Japan. 153 0093-934W91 $3.00 Copyright 0 IYYl by Academic Press. Inc. All rights of reproduction m any form reserved.
154
SHINDO, KAGA, AND TANAKA
II. METHODS
1. Subjects One patient with word deafness and three patients with auditory agnosia were studied. All were right-handed, and in all cases the cerebrovascular lesions involved at least the unilateral auditory cortex, or bilateral auditory cortices. The auditory brain stem responses (ABR) were normal in all patients. Conversational speech in these patients was fluent, with no paraphasia or confrontation naming observed. Reading aloud and reading comprehension in the patients were good to fully normal in the Standard Language Test of Aphasia in Japan. A profile of the patients is listed in Table 1.
2. Methods Three neuropsychological tests were used to assessthe auditory perception, comprehension, and lip reading ability of the patients. Each was tested at least 6 months after his or her cerebrovascular accident. (1) Speech discrimination test for auditory perception. Fifty-three Japanese nonsense monosyllables in a speech discrimination test devised by the authors (Tanaka, Shindo, & Kaga, 1981) were used. These 53 nonsense monosyllables for auditory perception are the most complex of 100 monosyllables that exist in the Japanese language, as determined by language science. The sounds in the test were tape-recorded and delivered to each ear separately through headphones at an intensity of 50 dB above the subjective threshold. Each patient was asked to respond orally or in writing. (2) Token Test for auditory comprehension. This test, devised by De Renzi and Vignolo (1962), was used to determine the degree of impairment of auditory comprehension. Each patient was tested using oral speech sounds with the examiner’s mouth concealed from the patient’s view. (3) Lip reading test. Lip reading tests composed of Japanese words of three syllables and short sentences, devised by Tanaka and Chiba (1975), were used (Table 2). The words in this test were selected for their high degree of difficulty in terms of auditory and/or visual discrimination (e.g., “usagi,” which means rabbit, and “unagi,” meaning eel, have the same mouth shape but sound different). The short sentences, of three to five syllables, were selected from reading ability tests for lower grade elementary school children (e.g., “Makotosanwa doubutsuen-e ikimashita,” meaning “Makoto went to a zoo”). These tests were performed three times in the following order: (1) lip reading only, (2) listening only, and (3) a combination of lip reading plus listening.
III. RESULTS
1. Controls (1) In normal subjects, the 53 nonsense monosyllables were identified correctly at a percentage rate of 84 2 7% (the average age was 29.5 years old; n = 20). No right ear/left ear differences were found. (2) In the Token Test, the percentage of correct responses in normal subjects was 98 + 3% (the average age was 44.9 years old; n = 54) (Hosokawa, Hosokawa, Rynichi, et al., 1981). (3) In the lip reading test, the percentage correct was only 17 * 7% for words and 40 + 17% for short sentences. The percentage correct in the listening only test was lOO%, and that for lip reading plus listening was also 100% (the average age was 27.5 years old; n = 23) (Tanaka, Chiba, 1975).
SPEECH DISCRIMINATION
155
AND LIP READING
TABLE 1 THE PATIENTS
LIST OF
Case Age 1 2 3 4
24 53 65 55
F F M M
Lesion
Cause
Sex
L, R: Auditory radiation Moyamoya disease Subarachnoidal hemorrhage L, R: T, L, R: T, Cerebral infarction L : T, Cerebral bleeding
Diagnosis Auditory agnosia Auditory agnosia Auditory agnosia Word deafness
TABLE 2 THE LIP READING
1. Usagi [rabbit] 2. Unagi [eel]
TESTS
A. Three-syllable Japanese words 3. Hashiru [run] 4. Ahiru [duck]
5. Hanashi [talk] 6. Hadashi [bare feet]
9. Byoin [hospital] 10. Byonin [patient]
11. Daikon [radish] 12. Raion [lion]
13. Tenki [weather] 14. Denki [electricity] 15. Genki [vigor]
16. Uwagi [coat] 17. Uwaki [fickleness]
18. Ikari [anger] 19. Hikari [light]
20. Garasu [glass]
22. Tabako [tobacco] 23. Tamago [egg]
24. Yasai [vegetables] 25. Yasashii [gentle]
7. Hanaji [nose bleed] 8. Katachi [shape]
21. Karasu [crow]
B. Japanese short sentences 1. Makotosanwa dobutsuen-e ikimashita. [Makoto-San went to a zoo.] 2. Kazega soyosoyoto fuite imasu. [The wind blows gently.] 3. Tokukara densyaga hashitte kimashita. [A tram has come from far away.] 4. Kyowa otosanno tanjobi desu. [Today is my father’s birthday.] 5. Ojiisanga yamamichio tobotoboto nobotte ikimasu. [An old man is going up a mountain path slowly.] 6. Ieno urani ogawaga nagarete imasu. [There is a stream behind a house.] 7. Kochirawa mainichi yukiga futte imasu. [It snows every day here.] 8. Okina namiga donto yosete kimasu. [A big wave breaks with a thud.] 9. Kosakuno jikanni mizudeppo-o tsukurimashita. [I made water pistols in the handicraft class.] 10. Koenwa furui oshirono atoni arimasu. [There is a park on the ruins of an old castle.]
156
SHINDO, KAGA, AND TANAKA
Discrimination
of mmosyl .lables
L:
2%
R:
2%
Tdetl Test : 22 x
;g,::, Lfi osy;n li,re$i,lg ‘i”‘g$” lip r~admg + Ilsleninp
lip~nreinc
Ihaten;g
I(p ryadw + llltenicq
FIG. 1. Results of case 1. (A) Illustration of the lesion sites demonstrated by CT scan. (B) Audiogram. (C) Discrimination of 53 Japanese nonsense monosyllables: L, left ear; R, right ear. Token Test. (D) Lip reading tests.
2. Case Report
In case 1 (Fig. l), a 24-year-old woman with moyamoya disease, the lesion was shown by CT scan to be located bilaterally in the auditory radiations. Pure tone audiometry showed normal hearing threshold. Monosyllable tests in both ears (with scores of 2% in each case) and the Token Test (a score of 22%) indicated severe impairment. In the lip reading tests, the score for lip reading plus listening for words was 48%, which was markedly better than those for lip reading only (12%) or for listening only (0%). For short sentences, the score for lip reading plus listening (20%) was a little better than those for lip reading only (0%) or for listening only (10%). In case 2 (Fig. 2), a 53-year-old woman with subarachnoidal hemorrhage, the lesion was located in the left auditory radiation and right T,. Pure tone audiometry showed an apparent sensory hearing deficit, but ABR was normal. The monosyllable test scores in both ears was 0%. On the other hand, the Token Test score was 57%. The score for lip reading plus listening for words was 68%, which was better than those for lip reading only (40%) or for listening only (24%). For short sentences, the score for lip reading plus listening (80%) was remarkably better than those for lip reading only (10%) or for listening only (10%).
SPEECH DISCRIMINATION
AND LIP READING
157
Case 2
D
Lip ReZIing Words
80
sentences
70 60 ‘50 30 20 10
40 1 FIG. 2. Results of case 2. (A) Illustration of the lesion sites demonstrated by CT scan. (B) Audiogram. (C) Discrimination of 53 Japanese nonsense monosyllables: L, left ear; R, right ear. Token Test. (D) Lip reading tests.
In case 3 (Fig. 3), a 65-year-old man with cerebral infarction, the lesion was bilaterally located in T,. Pure tone audiometry showed near normal hearing. The monosyllable test scores were only 8% in the right ear and 15% in the left ear. On the other hand, the Token Test score was 62%. The score for lip reading plus listening for words was 36%, which was better than those for lip reading only (0%) or for listening only (24%). For short sentences, the score for lip reading plus listening (20%) was a little better than those for lip reading only (0%) or for listening only (0%). In case 4 (Fig. 4), a 55year-old man with cerebral bleeding, the lesion was located in the left T,. Pure tone audiometry showed normal hearing. The monosyllable test scores were only 2% in both ears; the Token Test score was 51%. The score for lip reading plus listening for words was 68%, which was markedly better than those for lip reading only (0%) or for listening only (36%). In the test for short sentence lip reading showed a similar result: the score for lip reading plus listening (60%) was markedly better than those for lip reading only (0%) or for listening only (10%).
158
SHINDO, KAGA, AND TANAKA
Case 3
Discrimination
of mnosvll&les
L : 15% R:
8%
Taken Test : 62 %
HI
Lip Reading
FIG. 3. Results of case 3. (A) Illustration of the lesion sites demonstrated by CT scan. (B) Audiogram. (C) Discrimination of 53 Japanese nonsense monosyllables: L, left ear; R, right ear. Token Test. (D) Lip reading tests.
IV. DISCUSSION The present study demonstrated that among these patients, auditory comprehension improved when lip reading was combined with listening, as compared to lip reading alone or listening alone. 1. Speech Discrimination
and Lip Reading Ability
Ikemura (1983) reported that although hearing acuity among patients with word deafness or auditory agnosia was normal or mildly defective, the speech discrimination score ranged from O-40%, 50% in each ear. In the present study, the speech discrimination score using 53 nonsense monosyllables was 2-B% in these four patients. The auditory comprehension score of words or short sentences on the Token Test, however, was 22-62%. Similar results have been reported in other studies, indicating that patients with word deafness or auditory agnosia are unable either to listen to or to repeat nonsense syllables (Stockert, 1982) and nonsense words (Metz-Lutz & Dahl, 1984), as opposed to meaningful words and sentences. It is important, accordingly, that patients with word deafness or auditory agnosia are able to listen to some extent to speech consisting of meaningful words and sentences.
SPEECH DISCRIMINATION
AND LIP READING
159
Ib Lip
Reading
FIG. 4. Results of case 4. (A) Illustration of the lesion sites demonstrated by MRI. (B) Audiogram. (C) Discrimination of 53 Japanese nonsense monosyllables: L, left ear; R, right ear. Token Test. (D) Lip reading tests.
2. The Effect of Lip Reading on Auditory
Comprehension
Among the four patients in this study, three used lip reading in their daily lives as a means of communication. In the case of simple conversation, they could understand family members or acquaintances by reading their lips. For more complicated conversation, however, they relied on written communication. It has been reported that among patients with word deafness or auditory agnosia, lip reading is commonly used to help understand ordinary conversation (Tanaka et al., 1964; Michel et al., 1980; Stockert, 1982; Auerbath et al., 1982; Marshall et al., 1985). It is further reported that such patients usually understand only simple words by lip reading (Metz-Lutz et al., 1984) and rely on writing in most conversations (Tanaka et al., 1964; Leicester, 1980; Shindo, Kaga, & Tanaka, 1981). In this study, the lip-reading-only scores in these patients were lower than those among controls in tests of both words and short sentences. The scores for lip reading combined with listening, however, were better than those for lip reading only or listening only in tests of both words and short sentences. Auerbach et al. (1982) reported that by combining
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listening with lip reading, auditory comprehension could be improved in patients with pure word deafness. Erber (1969) reported that the score of listening to spoken spondaic words was higher with listening plus lip reading than with listening only among normal subjects. Furthermore, Sanders and Goodrich (1971) reported that the listening score of frequency distortion sounds of phonetically balanced words was better with listening plus lip reading than with listening only, being statistically significant at the 0.01 level among normal subjects. Therefore, comprehension of speech sounds may possibly be improved if residual hearing acuity is combined with lip reading, not only in patients with peripheral hearing disorders but also in those with word deafness or auditory agnosia. Experimental investigation of the lip reading abilities of adults with normal hearing has demonstrated that in ordinary speech, they use visual cues from lip reading about 25% of the time (Dodd, 1977). It is now well established that adults with normal hearing use lip-read cues to augment their perception of speech. Therefore, lip reading helps in the perception of speech, and this ability appears to remain preserved in patients with word deafness or auditory agnosia. In conclusion, it is emphasized that patients with word deafness, or with auditory agnosia without aphasia, may use lip reading to improve their comprehension of speech. REFERENCES Auerbach, S. H., Allard, T., Naeser, M., Alexander, M. P., & Albert, M. L. 1982. Pure word deafness-Analysis of a case with bilateral lesions and a defect at the prephonemic level. Bruin, 105, 271-300. Campbell, R., Landis, T., & Regard, M. 1986. Face recognition and lipreading-A neurological dissociation. Bruin, 109, 509-521. De Renzi, E., & Vignolo, L. A. 1962. The Token Test: A sensitive test to detect receptive disturbances in aphasics. Brain, 85, 665-678. Dodd, B. 1977. The role of vision in the perception of speech. Perception, 6, 31-40. Dodd, B. 1987. Lip-reading, phonological coding and deafness. In B. Dodd & R. Campbell (Eds.), Hearing by eye: The psychology of lip-reading. London: Lawrence Erlbaum Associates. Pp. 177-189. Erber, N. P. 1969. Interaction of audition and vision in the recognition of oral speech stimuli. Journal of Speech and Hearing Research, 12, 423-425. Hosokawa, T., Hosokawa, K., Rynichi, N., et al. 1981. The Token Test in preschool and adult aphasics. In C. C. Peng (Ed.), Current issues in neurolinguistics: A Japanese contribution. Tokyo: The ICU Language Sciences Summer Institute. Pp. 69-95. Ikemura, Y. 1983. The development of the study of pure word deafness. Psychiatry, 25, 351-361. Leicester, J. 1980. Central deafness and subcortical motor aphasia. Bruin and Language, 10, 224-242. Marshall, R. C., Rappaport, B. Z., & Garcia-Bunuel, L. 1985. Self-monitoring behavior in a case of severe auditory agnosia with aphasia. Brain and Language, 24, 297-313. Metz-Lutz, M., & Dahl, E. 1984. Analysis of word comprehension in a case of pure word deafness. Brain and Language, 23, 13-25.
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Michel, F.. & Peronnet, F. 1980. A case of cortical deafness: Clinical and electrophysiological data. Brain and Language, 10, 361-317. Sanders, D. A., and Goodrich, S. J. 1971. The relative contribution of visual and auditory components of speech to speech intelligibility as a function of three conditons of frequency distortion. Journal of Speech and Hearing Research, 14, 154-159. Shindo. M., Kaga, K., & Tanaka. Y. 1981. Auditory agnosia following after bilateral temporal lobe lesion-Report of a case. Brain and Nerve, 33, 139-147. Stockert. T. R. 1982. On the structure of word deafness and mechanisms underlying the fluctuation of disturbances of higher cortical functions. Brain and Language, 16, 133146. Tanaka, Y., & Chiba F. 1975. Speechreading test using a video tape recorder and its application to hearing aid evaluation. Audiology Japan, 18, 195-202. Tanaka, Y., Shindo, M., & Kaga, K. 1981. Clinical tests of central auditory dysfunction. F. Ota (Ed.), Brain and auditory dysfunction. Tokyo: Shinohara Publisher. Pp. 655 102. Tanaka, Y., Taguchi, K., Sakabe, N., & Igarashi, E. 1964. Pure auditory agnosia associated with alteration of voice and personal character, Folia fhoniatrica, 17, 185-194.
