The perceptual tone‐noise ratio of iterated rippled noise in listeners with hearing loss.

Abstract

Previous work has demonstrated that iterated rippled noise (IRN) produces a weaker pitch in hearing‐impaired (HI) listeners than in normal‐hearing (NH) subjects (e.g., Leek and Summers, 2001). In this study, the hypothesis was tested that the weaker pitch is a result of an increased perceptual noisiness of IRN for HI subjects. The tone‐noise ratio (T/N) was developed by Patterson et al. (1996) to describe the relationship between the strength of the tone component and the strength of the noise component for a given IRN. The T/N was measured using an adaptive procedure to find the tone‐plus‐noise level that matched each IRN stimulus. Four NH and 4 HI subjects took part in the study. The stimuli were IRNs with delays ranging from 4 to 16 ms and with one to eight iterations. There was a significant effect of delay and of iteration number, with longer delays and more iterations producing greater T/N. There were no significant differences between subject groups. These findings suggest that the weaker complex pitch observed in listeners with hearing loss is not due to an abnormally noisy IRN percept but must be attributed to other impaired processing mechanisms. [Work supported by NIH.]