Spectral weighting functions for localization of complex sound: Effects of sensorineural hearing loss

When localization cues are distributed across the spectrum of a complex sound, listeners with normal hearing (NH) utilize cues near the 600-800 Hz “ITD dominance region” [Bilsen and Raatgever, Acustica 28, 131–132 (1973)]. Recent work has quantified this pattern using spectral weighting functions (SWFs) [Folkerts and Stecker, ARO 42, 505 (2018)] in NH listeners. However, the salience of the ITD dominance region in listeners with sensorineural hearing loss (SNHL) remains unexamined. Folkerts and Stecker [ARO 45, 171 (2022)] used simulated SNHL in NH listeners to measure impacts of elevated hearing thresholds, loudness recruitment, and reduced high-frequency ITD sensitivity [Steinberg and Gardener, J Acoust. Soc Am 9, 11–23 (1937)] on SWFs. The current study measured SWFs in listeners with bilateral sloping high-frequency SNHL. Direct comparisons to SWFs measured with simulated SNHL test the hypothesis that reduced audibility of high-frequency components shifts the ITD dominance region to lower frequencies (i.e., 400–600 Hz). Individual SWFs measured in listeners with SNHL are compared to their headphone and free field thresholds to assess whether audibility can account for weighting changes. [Work supported by NIH R01-DC016643.]