Impact of mild to moderate sensorineural hearing loss on single and multiple pitch perception

Everyday auditory scenes often contain multiple sound sources, each with a different fundamental frequency (F0) and corresponding pitch. The ability to focus on one talker in competing sounds or listen to harmony in music partly relies on isolating one pitch from a mixture. Mild to moderate hearing loss (HL) degrades spectrotemporal cues and adversely affects single-pitch perception. Although extensive research has been conducted on speech perception in listeners with HL and the efficacy of hearing aids, little is known so far about how HL affects the perception of multiple-pitch combinations and whether hearing aids alleviate these deficits. In this behavioral study, we measured aided and unaided thresholds in listeners with mild to moderate HL for four tasks that involved single-pitch stimuli and multiple-pitch combinations. Preliminary data suggest that HL results in mild deficits in single-pitch perception that become severe for multiple pitches, with hearing aids providing little to no improvement. These findings highlight the need to better characterize neural mechanisms of multiple pitch perception to inform effective restoration of these cues in listeners with HL. [Work supported by NIH grant R00DC017472 (AHM)]