A digital hearing aid with 8-band curvilinear loudness fitting

Abstract

Owing to technological advances in very large-scale integrated (VLSI) circuits, high-speed digital signal processing (DSP) chips become fast enough to allow for real-time implementation of hearing aid algorithms in units small enough to be wearable. In this paper, a body-worn type digital hearing aid (DHA) based on a dedicated DSP chip is developed. A fitting software running on a PC supported by the Win95 OS is also developed. The fitting protocol is based on the NAL-R procedure applied to eight frequency bands, but it is designed to support a curvilinear fitting to cope with the nonlinear perception of hearing-impaired listeners. Preliminary subjective tests regarding the speech intelligibility and perceived quality revealed that the new DHA could be of benefit to hearing aid users.