Tutorial on the potential deterioration in hearing due to hearing aid usage.

This manuscript examines the issue of potential decline in hearing sensitivity due to hearing aid usage through an analysis of data obtained from the temporary threshold shift (TTS) paradigm. Following a critique of the traditional measures of TTS, the concept of integrated TTS (ITTS) is reviewed and data on hearing-aid-induced ITTS are presented. In addition, a series of equations relating permanent threshold shift (PTS) to a recently developed measure of noise dose (Dn) is derived and predictions for hearing-aid-induced PTS are made. Recommended gain settings established to protect the hearing of a person wearing a hearing aid from further decline following various durations of hearing aid usage are also provided.