The pathogenesis of hyperacusis has not yet been clearly elucidated, nor have evaluation and treatment methods been established. The purpose of this study was to investigate the efficacy of pharmacotherapy for hyperacusis. The subjects were 15 patients, including 9 males men and 6 females women, with a mean age of 48.9 ± 17.5 years, who visited the Department of Otorhinolaryngology, Tokai University, between April X and November X + 1 with the chief complaint of auditory hypersensitivity. The mean symptom duration at the time of the visit was 19.7 ± 20.8 months. The associated distress and depression/anxiety levels, and the cause of the auditory hypersensitivity were investigated, and the therapeutic effects of lifestyle changes and initial drug treatment were examined. The distress and depression/anxiety levels were assessed using questionnaires (Khalfa Hyperacusis Questionnaire Score [HQ score; cutoff 16 points], HADS Japanese version). The initial treatment included amitriptyline, clonazepam, and valproic acid, and the treatment responses were assessed after 4 weeks. The HQ score decreased significantly from 20.5 ± 7.1 before treatment to 14.1 ± 5.6 after 4 weeks of treatment (P ± 0.05). The score for anxiety changed from 8.2 ± 5.1 before to 6.4 ± 4.5 points after treatment (ns) and that for depression changed from 8.6 ± 5.3 before to 5.8 ± 3.2 points after treatment (ns). Overall, the auditory hypersensitivity itself improved in some cases with or without improvement of depression/ anxiety.

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　　Most bimodal users who use a combination of cochlear implants (CIs) and hearing aids (HAs) are said to have poor sound localization as compared with bilateral cochlear implant or bilateral hearing aid users, while having the advantage of binaural hearing effects⁵⁾.

　　ILD (interaural level difference) and ITD (interaural time difference) play an important role in sound source localization, and we examined the sound source localization in relation to the ITD in this study. In bimodal users, there is a time difference between the left and right due to a difference in the signal processing speed between the CI and HA. In other words, the auditory nerve is directly stimulated on the CI side and the processing speed is faster than the case on the HA side, which is considered to be disadvantageous for sound source localization⁵⁾. Also, in cases using a combination of a CI (MED-EL) and HA, the CI processing speed is usually known to be 3 to 10 ms faster than that of the HA⁶⁾, and a Bimodal Fitting system has been introduced into the mapping software to adjust for the CI processing speed. In this study, three patients were subjected to a directional test before and after adjustment for the CI processing speed in a Bimodal Fitting system. Evaluation by misalignment of wrong answers (the RMS value) suggested that the sound source localization may have improved.

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　　In this study, tasks involving listening to environmental sounds were administered to elderly individuals, twelve hearing aid (HA) users, eleven cochlear implant (CI) users, and fifteen normal hearing subjects. The results were compared among the three groups, and the effects of the acoustic characteristics of the environmental sounds were analyzed. The results showed that the perception of environmental sounds was significantly decreased in the HA and CI users as compared with that in the normal hearing group, regardless of which the hearing device was being used. In the relationship between listening of environmental sounds and acoustic characteristics, hearing aid group and cochlear implant group showed similarity. Intermittent sounds in acoustic pressure fluctuation characteristics and slow-propagating sounds in amplitude envelop characteristics showed better results than other acoustic features. Those results suggested that differences in acoustic characteristics contributed to the perception of environmental sounds.

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　　We established age-dependent and side-dependent reference values for auditory processing test (APT) batteries. This study was conducted in 53 subjects aged 20-59 years with normal hearing. The results of the APT were used to establish reference values for each 10-year age group, using the 2SD method. Reference values for the tests performed on one ear at a time were established separately as the “superior” or “inferior” side, depending on the results for each test item.

　　Statistical differences among age groups were noted in the following test items: dichotic listening test, speech recognition under multi-talker noise (signal to noise ratio of +15dB, +10dB, and +5dB) of the Hatta-Ota version of APT, dichotic listening monosyllable test, fast speech recognition test (2x speed, mid-word), and speech recognition under speech noise of the Obuchi version of APT. The dominant test performance side was almost equally distributed between the right and left sides, even though most of the participants were right-handed. Based on these results, we propose different reference values for the APT for different age groups. We further propose setting up separate reference values for tests conducted on one ear at a time by the superior and inferior sides for each test item.

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