Effect of long-term training on sound localization performance with spectrally warped and band-limited head-related transfer functions

Abstract

Sound localization in the sagittal planes, including the ability to distinguish front from back, relies on spectral features caused by the filtering effects of the head, pinna, and torso. It is assumed that important spatial cues are encoded in the frequency range between 4 and 16 kHz. In this study, in a double-blind design and using audio-visual training covering the full 3-D space, normal-hearing listeners were trained 2 h per day over three weeks to localize sounds which were either band limited up to 8.5 kHz or spectrally warped from the range between 2.8 and 16 kHz to the range between 2.8 and 8.5 kHz. The training effect for the warped condition exceeded that for procedural task learning, suggesting a stable auditory recalibration due to the training. After the training, performance with band-limited sounds was better than that with warped ones. The results show that training can improve sound localization in cases where spectral cues have been reduced by band-limiting or remapped by warping. This suggests that hearing-impaired listeners, who have limited access to high frequencies, might also improve their localization ability when provided with spectrally warped or band-limited sounds and adequately trained on sound localization.

Accommodating to new ears: The effects of sensory and sensory-motor feedback

“…Contrary to the present work, neither of those studies observed improvements in polar angle errors, but this is probably more of a reflection of the differences in sensitivity of the localization performance measures in those studies compared to the current study. In a related and very recent study, Majdak et al (2013) used a similar training paradigm to help subjects accommodate to virtual auditory space stimuli that were either low passed at 8 kHz or where the DTFs were spectrally warped to shift the high frequency spectral information (2.8-16 kHz) into a narrower, low frequency region (2.8-8 kHz). Using measures similar to those used here, they showed training effects on both the PAE and %FB comparable to those reported here, although their training consisted of 21 days of two hour training sessions using a virtual display of visual and auditory stimuli.…”

Acoustic analysis of the directional information captured by five different hearing aid styles

“…Previous work has demonstrated that listeners are able to recalibrate to new HRTFs following a relatively prolonged period of exposure Carlile et al, 2007;Carlile and Blackman, 2014;Majdak et al, 2013). Presumably the quality of that spatial information will be dependent on both the extent of the locationdependent changes and the uniqueness of the spectral profiles for each location.…”

Intentional Switching in Auditory Selective Attention: Exploring Different Binaural Reproduction Methods in an Anechoic Chamber

“…Further information about the CTC-filter were presented by Majdak et al [42]. The used HRTFs were those of the artificial head described in reproduction method III.…”