Citation

Dobreva MS, O'Neill WE, Paige GD. J. Neurophysiol. 2011; 105(5): 2471-2486.

Affiliation

1University of Rochester School of Medicine and Dentistry.

Copyright

(Copyright © 2011, American Physiological Society)

DOI

10.1152/jn.00951.2010

PMID

21368004

PMCID

PMC3094163

Abstract

Errors in sound localization, associated with age-related changes in peripheral and central auditory function, can pose threats to self and others in a commonly encountered environment such as a busy traffic intersection. This study aimed to quantify the accuracy and precision (repeatability) of free-field human sound localization as a function of advancing age. Head-fixed young, middle-aged, and elderly listeners localized band-passed targets using visually-guided manual laser pointing in a darkened room. Targets were presented in the frontal field by a robotically-controlled loudspeaker assembly hidden behind a screen. Broadband targets (0.1-20 kHz) activated all auditory spatial channels, whereas low-pass and high-pass targets selectively isolated interaural time and intensity difference cues (ITDs and IIDs) for azimuth, and high-frequency spectral cues for elevation. In addition, in order to assess the upper frequency limit of ITD utilization across age groups more thoroughly, narrowband targets were presented at 250 Hz intervals from 250 Hz up to ∼2 kHz. Young subjects generally showed horizontal overestimation (overshoot) and vertical underestimation (undershoot) of auditory target location, and this effect varied with frequency band. Accuracy and/or precision worsened in older individuals for broadband, high-pass, and low-pass targets, reflective of peripheral but also central auditory aging. In addition, when compared to young adults, middle-aged and elderly listeners showed pronounced horizontal localization deficiencies (imprecision) for narrowband targets within 1250-1575 Hz, congruent with age-related central decline in auditory temporal processing. Findings underscore the distinct neural processing of the auditory spatial cues in sound localization and their selective deterioration with advancing age.

Language: en