Description

---

A hearing aid is the most fundamental technology available in the management of persons with sensory hearing impairment. The data conversion process and the signal processing transformations associated with digital signal processing (DSP) are potential sources of signal distortion in hearing aids. Distortion of the signal in its temporal domain is one such distortion. Wide Dynamic Range Compression (WDRC) is the amplification strategy with which the hearing aid compresses the wide dynamic range of conversational speech to the reduced dynamic range of the user. Alteration of the temporal envelope of the speech signal is a major side effect of fast-acting WDRC. None of the existing measures indicates the magnitude of temporal distortion making it difficult for the hearing impaired as well as audiologists to compare different models of hearing aids for an appropriate selection.
A short review of the factors that contribute to the non-adoption of hearing aids as well as dissatisfaction with hearing aid performance suggests that issues related to processing/amplification of short-duration temporal events of speech in hearing aids are crucial. There is a need not only to identify temporal events in a speech whose alterations may result in distortion in the hearing aid output speech but also to quantify the same. There is also a need to investigate the significance of the alteration of each of these temporal events for speech identification.