Word recognition in continuous and interrupted broadband noise by young normal-hearing, older normal-hearing, and presbyacusic listeners

Objective: Word recognition performance in continuous and interrupted broadband noise was examined in young normal-hearing (YNH), older normal-hearing (ONI), and presbyacusic (older hearing-impaired [OHI]) listeners. Design: Participants (N = 36) were presented with identical Northwestern University Auditory Test No. 6 stimuli at 30 dB sensation level re their respective speech reception thresholds. The speech stimuli were presented in quiet and in both competing noise conditions with signal to noise ratios (S/Ns) of 10, 5, 0, -5, -10, -15, and -20 dB. Results: In general performance was superior in quiet, improved with increasing S/N, and was greater in the interrupted broadband noise than in the continuous broadband noise. Significant main effects of group and S/N were found in both competing noises (p < 0.0001). Post hoc pairwise comparisons revealed all groups performed differently, with superior performance being displayed by the YNH group followed by the ONH and OHI groups, respectively (p < 0.05). A significant group by S/N interaction was observed in only the interrupted noise condition (p = 0.019). The degree of change in word recognition performance as a function of S/N was greatest in the OHI group followed by the ONH group and the YNH group. Conclusions: Group effects observed in the interrupted noise would imply that the two older groups of listeners had an auditory temporal deficit relative to the YNH listeners. The paradigm reveals the patency of the temporal processes that are responsible for the perceptual advantage (i.e., a release from masking) a listener has in interrupted competing stimulus.