Effect of localization training in horizontal plane on auditory spatial processing skills in listeners with normal hearing

Abstract

Introduction: Source localization depends on processing of monaural and binaural spatial cues. Although difficulties arising due to the deficits in the processing spatial cues are well documented in the literature, remediation programs aimed at resolving spatial deficits are scanty. The present study is a preliminary research aimed at exploring the changes in the spatial performance of normal-hearing listeners using localization training in a horizontal plane. Methods: Twelve normal-hearing listeners aged 18–25 years participated in the study. The study was conducted in three phases including pretraining, training, and posttraining phase. At the pre- and post-training phase, three tests of spatial skills, namely, test of localization in free-field, test of lateralization ability under headphones (i.e., virtual auditory space (VAS) identification test), and tests for binaural processing ability (i.e., interaural level difference [ILD] and interaural time difference [ITD]), were administered. The training phase consisted of structured localization regimen spanning eight sessions spread over 2 weeks. Results: Paired t-test revealed that root mean square error, ITD threshold, and VAS scores in the post-training phase were significantly better than pretraining condition, indicative of the benefit derived from training. ILD did not alter significantly in posttraining phase owing to the ceiling effect in pretraining phase. Conclusion: The localization training protocol used in the present study on a preliminary basis proves to be effective in normal-hearing listeners and its implications can be extended to other clinical populations as well.