Error Metrics for Impaired Auditory Nerve Responses of Different Phoneme Groups

An auditory nerve model allows faster investigation of new signal processing algorithms for hearing aids. This paper presents a study of the degradation of auditory nerve (AN) responses at a phonetic level for a range of sensorineural hearing losses and flat audiograms. The AN model of Zilany & Bruce was used to compute responses to a diverse set of phoneme rich sentences from the TIMIT database. The characteristics of both the average discharge rate and spike timing of the responses are discussed. The experiments demonstrate that a mean absolute error metric provides a useful measure of average discharge rates but a more complex measure is required to capture spike timing response errors.