Adaptive Dynamic Range Optimisation for hearing aids

Abstract

ADRO (Adaptive Dynamic Range Optimisation) is a slowly-adapting digital signal processor that controls the output levels of a set of narrow frequency bands so that the levels fall within a specified dynamic range. ADRO is suitable for a variety of applications, including control of a hearing aid. In the case of a hearing aid, the output dynamic range is defined by the threshold of hearing (T) and a comfortable level (C) at each frequency for the individual listener. A set of rules is used to control the output levels, with each rule directly addressing a requirement for a functional hearing aid. For example, the audibility rule specifies that the output level should be greater than a fixed l..