Clinical Trial of a Low-cost, High Power Compression Hearing Aid

Abstract

This paper describes the outcome of a clinical trial of a low-cost high power compression behind-the ear-hearing aid (BTE-HA), performed in order to assure the quality of the product. Twenty-one experienced HA users, 14 males and 7 females at a median age of 77 years, (range 50–86 years) were recruited among persons fitted with HAs within a period of 6–12 months prior to recruitment. Seventeen had been fitted previously with binaural DSP-HAs, whereas four had a monaural fitting with analogue HAs. All subjects had a hearing loss >50 db at 2 kHz. Validation of the fitting according to the NAL-R prescription or POGO prescription was performed by insertion gain measurements, showing that the HA meets the frequency and amplification characteristics required according to an individual hearing loss. The immediate improvement in SRS in quiet on an individual basis was median 52% (range 8–96) and in background noise (S/N=5 dB) median 43% (range 0–76). A comparison between the benefits obtained with the test-HA and the previously fitted HA showed no significant differences. The user was allowed a 6–8 weeks period of experiences with the aid and then completed the IOI-HA resulting in a total median score of 3.9 (range 2.6–4.7). Six preferred to keep the test-HAs replacing the previously fitted modern HAs. It is concluded that this low-cost, high power HA offers benefit to persons with sensorineural hearing loss >50 dB at 2 kHz and that the frequency and amplification characteristics meet the requirements of the WHO.

• low-cost HAs
• clinical trial
• quality assurance