Clinical features of acute profound deafness related to immunological impairments were investigated in 14 cases which satisfied the diagnostic criteria proposed by the Committee of “Acute Profound Deafness” of Japanese Ministry of Health and Welfare.
The results obtained were as follows;
1) Both ears satisfied the diagnostic criteria in only 5 cases out of 14 in spite of bilateral hearing impairments in all cases.
2) There were no remarkable features in onset of hearing loss or in associated symptoms at the onset of hearing loss.
3) Associated autoimmune disease was confirmed in only 4 cases out of 14. However, abnormal test results which suggested the existence of immunological impairments were found in all cases.
4) The positive TPHA tests were found in 3 cases out of 4 male patients.
5) The mean age at the onset of hearing loss was 39.0 years old.
6) The mean time interval of onset of hearing loss in both ears was 1 year and 10 months except 3 cases.
7) When the best record of pure tone audiogram was compared with the worst one after the start of steroid therapy, about 29dB was found as the fluctuation in mean hearing level at 5 frequencies between 250Hz and 4 kHz.
8) When the final audiogram was compared with the initial one, only 6 dB was found as the deterioration in mean hearing level at 5 frequencies between 250 Hz and 4 kHz.

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The auditory brainstem responses (ABR) by the ipsilateral or the bilateral synchronous recordings produced some remarks on the origin of ABR.
The subjects were composed of five patients with cerebello-pontine angle tumors, one with epipharyngeal cancer and 10 with normal ear.
Investigation of ABR-waves comparing with magnetic resonance imaging (MRI) revealed some findings on the origin of the ABR waves.
From the results of ABR-recording on the nonaffected side, it was assumed that wave IV and V were derived from the neighbouring area of the superior olivary complex and the lateral leminiscus.
It was suggested that the enlarged amplitude of ABR-waves on the non-affected side was one of the significant findings of the cerebello-pontine angle tumors.
The present study suggested us to perform both ispi- and contra-lateral ABR recording, in order to investigate the origin of the waves.

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A speech audiometry trial is described for testing the degree of hearing loss and its pathogenesis. The recorded natural voice was used for the test. However, natural speech have no universality and reproductibility, whereas synthetic speech has.
I have been using synthetic words for speech audiometry, and synthetic speech audiometry for normal hearing adults was examined. The synthetic speech audiometry was performed with various sounds as follows, 1. non-distorted vowels, 2. filtered vowels and time compressed vowels, 3. nondistorted synthetic 57-system list, 4. non-distorted synthetic 67-system list, and 5. interval changed 67-system list.
The results of these synthetic speech audiometry were as follows.
1. Correct replying rate of non-distorted vowels were 100%.
2. Correct replying rate of non-distorted consonants (CV-syllable) were 83%.
3. Synthetic speech audiometry might be useful for diagnosis of retrocochlear dysacusis.

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Various types of audiometric tests have been devised for the diagnosis of retrocochlear dysacusis. Among these, the speech audiometry have been used with phonetic discs of natural voice recorded according to word lists such as 57-System List and 67-System List. The recorded natural voice is manipulated to some extent for distorted speech audiometry. In the present study, 67-System List (monosyllabic word list and figure list) was produced with speech synthesizer DECtalk.
Speech audiometry and synthesized speech audiometry were conducted to compare articuration of normal subjects, patients with cochlear hearing loss, conductive hearing loss, presbyacusis and retrocochlear hearing loss.
The results demonstrated that patients with retrocochlear lesions had significantly decreased articulation of synthetic speech compared with normal speech. In addition, the audiometry using synthetic speech with varied intervals indicated retrocochlear hypofunction in patients with presbyacusis, as reported previously.

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The applicable age and reliability of peep-show test with receiver were investigated in young children. In 328 cases (328 eares: mean hearing level 96.6dB) consulted us under 3 years of age from 1971 to 1984 puretone audiometry was regularly tested at least for 3 years.
The results obtained as follows:
1) The threshold of peep-show test with receiver could be measured under 3 years of age in 86% of all cases. The remainder of children were not able to be measured because of repeating the test at too long interval or rejecting the usage of receiver.
2) The difference between the first and the last threshold of peep-show test with receiver was under ±10dB at 500Hz, 1kHz, 2kHz and 4kHz in 72.4-87.7% of all cases. If children had no problem except for hearing impairment and their hearing ability were fixed, it was concluded that most of their thresholds of peep-show test with receiver can be measured reliably under 3 years of age.

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Two patients complaining of a fluctuating hearing loss and repeated attacks of dysequilibrium and vertigo, had been estimated as Ménière's disease at first, but a diagnosis was made finally the vertebro-basilar artery insufficiency in their clinical course.
Electrocochlegraphy was very useful for the elucidation of the pathophysiology of hearing loss in these cases.
In the first case (a 47-year-old female), the auditory nerve action potential (AP) and cochlear microphonics (CM) showed a low amplitude and a high detection threshold being severe (advanced) hearing loss, but improved almost completely. For the reason why hearing impairment was recovered, it was thought to be due to reversible change of striae vascularis caused by blood supply insufficiency of the vertebro-basilar artery.
In the second case (a 53-year-old male), AP showed a broad wave form with a dominant negative summating potential and the detection threshold of CM was remarkably lower than that of the pure tone audiogram. These findings seemed to suggest damage of the cochlear nerve by vertebro-basilar artery insufficiency.

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Depressive condition in tinnitus patients was examined with the use of depression score test (modified MAS test for Japanese). 70 (53.4%) of 131 patients were found to be in depressive condition. In order to examine the effect of anti-depressant drug to tinnitus patients, a double blind study was carried out using Sulpiride (150mg) and non-active placebo. The number of cases evaluated for clinical efficacy were 45 (23 treated with Sulpiride and 22 treated with placebo).
The effective rate of Sulpiride and placebo were 52.2% and 40.9%, respectively. However, there was no significant difference between Sulpiride and placebo in clinical effects. However, many complaints of depressive patients were clearly improved with Sulpiride.

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The equation obtaining Tympanogram (TG) was deduced, and the effect of each part of middle ear upon TG was examined. Furthermore, TGs of specific middle ear diseases, e.g. ossicular chain disorders and secretoty otitis media (SOM) were simulated, and the effectiveness of tympanometry upon the diagnosis of middle ear diseases was evaluated. The following conclusions were obtained.
(1) TG is theoretically obtainable.
(2) Factors which have a relatively large effect upon static compliance (SC) of TG are eardrum radius, eardrum thickness, eardrum Young's modulus, mastoid cavity volume, ossicular chain angular stiffness, pressure dependent coefficient of ossicular chain, and quantity of effusion.
(3) The reason why the diagnosis of ossicular chain disorders from TG is difficult is theoretically clarified.
(4) In case with SOM, various types of TG are able to exist. However, C type of small valued SC and B type are presented, only when the middle ear cavities are filled with effusion.

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