A Method for Assessing Auditory Spatial Analysis in Reverberant Multitalker Environments.

BACKGROUND: Deficits in spatial hearing can have a negative impact on listeners' ability to orient in their environment and follow conversations in noisy backgrounds and may exacerbate the experience of hearing loss as a handicap. However, there are no good tools available for reliably capturing the spatial hearing abilities of listeners in complex acoustic environments containing multiple sounds of interest.

PURPOSE: The purpose of this study was to explore a new method to measure auditory spatial analysis in a reverberant multitalker scenario.

RESEARCH DESIGN: This study was a descriptive case control study.

STUDY SAMPLE: Ten listeners with normal hearing (NH) aged 20-31 yr and 16 listeners with hearing impairment (HI) aged 52-85 yr participated in the study. The latter group had symmetrical sensorineural hearing losses with a four-frequency average hearing loss of 29.7 dB HL.

DATA COLLECTION AND ANALYSIS: A large reverberant room was simulated using a loudspeaker array in an anechoic chamber. In this simulated room, 96 scenes comprising between one and six concurrent talkers at different locations were generated. Listeners were presented with 45-sec samples of each scene, and were required to count, locate, and identify the gender of all talkers, using a graphical user interface on an iPad. Performance was evaluated in terms of correctly counting the sources and accuracy in localizing their direction.

RESULTS: Listeners with NH were able to reliably analyze scenes with up to four simultaneous talkers, while most listeners with hearing loss demonstrated errors even with two talkers at a time. Localization performance decreased in both groups with increasing number of talkers and was significantly poorer in listeners with HI. Overall performance was significantly correlated with hearing loss.

CONCLUSIONS: This new method appears to be useful for estimating spatial abilities in realistic multitalker scenes. The method is sensitive to the number of sources in the scene, and to effects of sensorineural hearing loss. Further work will be needed to compare this method to more traditional single-source localization tests.