Nonlinear digital hearing aid with near-instantaneous amplitude compression.
We designed a new type of nonlinear digital hearing aid (TD-1) with near-instantaneous amplitude compression for sensorineural hearing-impaired people. The amplification method utilized by the TD-1 normalizes the signal waveforms within a time window bounded by two adjacent positive going zero-crossing points. The signals within this window are amplified so that the maximum amplitude reaches a preset value, thus allowing a consistent peak amplitude to be maintained. To test this, we examined the efficacy of the TD-1 device in 31 patients with sensorineural hearing loss. When tested for recognition of Japanese sentences in a quiet environment, 7 of 25 (28.0%) subjects wearing the TD-1 showed a 20% or greater increase in the maximum intelligibility score than that obtained when wearing their own linear hearing aids. In addition, 7 of 31 (22.6%) subjects showed the same increase with the TD-1 relative to that obtained when they wore HA70 or HA73 devices (Rion Co., Ltd., Tokyo, Japan), which are conventional analogue hearing aids. These results indicate that TD-1 can be effective for patients with sensorineural hearing loss.
Kaneko
K
K
Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine, Kyoto University, Japan. kaneko@hs.m.kyoto-u.ac.jp
Shoji
K
K
Kojima
H
H
Inoue
M
M
Asato
R
R
Hirano
S
S
Tateya
I
I
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001309:Auditory Threshold; D002648:Child; D015331:Cohort Studies; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006310:Hearing Aids; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000534:rehabilitation*; D006801:Humans; D008144:Loudness Perception; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D016896:Treatment Outcome