Temporal mechanisms underlying recovery from forward masking in multielectrode-implant listeners

This paper describes a detailed study of recovery from forward masking in s ix users of the Nucleus-22 cochlear implant with a range of performance in speech-recognition tests. Recovery from a 300-ms-long pulse train presented at 1000 pps was found to be fastest in the poorer performers. The shape of the recovery function was found to be most strongly influenced by masker d uration, suggesting that temporal integration plays a prominent role in rec overy from forward masking. The recovery functions are reasonably well desc ribed by a sum of two exponentially decaying processes. Their relative weig hts depend on the amount of temporal integration occurring during the maske r, and show strong intersubject variability. Nonmonotonicities sometimes ob served in the recovery functions may be accounted for by considering the in fluence of neural adaptation. (C) 1999 Acoustical Society of America. [S000 1-4966(99)00403-8].