Pitch strength and pitch dominance of iterated rippled noises in hearing-impaired listeners

Reports using a variety of psychophysical tasks indicate that pitch percept ion by hearing-impaired listeners may be abnormal, contributing to difficul ties in understanding speech and enjoying music. Pitches of complex sounds may be weaker and more indistinct in the presence of cochlear damage, espec ially when frequency regions are affected that form the strongest basis for pitch perception in normal-hearing Listeners. In this study, the strength of the complex pitch generated by iterated rippled noise was assessed In no rmal-hearing and hearing-impaired listeners. Pitch strength was measured fo r broadband noises with spectral ripples generated by iteratively delaying a copy of a given noise and adding it back into the original. Octave-band-p ass versions of these noises also were evaluated to assess frequency domina nce regions for rippled-noise pitch. Hearing-impaired listeners demonstrate d consistently weaker pitches in response to the rippled noises relative to pitch strength in normal-hearing listeners. However, in most cases, the fr equency regions of pitch dominance, i.e., strongest pitch, were similar to those observed in normal-hearing listeners. Except where there exists a sub stantial sensitivity loss, contributions from normal pitch dominance region s associated with the strongest pitches may not be directly related to impa ired spectral processing. It is suggested that the reduced strength of ripp led-noise pitch in listeners with hearing loss results from impaired freque ncy resolution and possibly an associated deficit in temporal processing.