Diagnostic value of experimental parameters for measurement of localization ability

This research examines the test parameters in two methods proposed by an ANSI/ASA working group for measurement of auditory localization with tactical communications and hearing protection systems (TCAPS). The localization task consisted of responding to pink noise bursts (0.250s and 7000s). Participants responded by pointing to the perceived source with a laser pointer mounted on an instrumented chair. 12 participants completed the study—half of the trials while wearing no headset and half while wearing an active Invisio X5 headset. Method 1 used four pairs of loudspeakers, separated by 8°, 10°, or 12°, and the listener was tested in two orientations (0° and 45°). Intended for use in untreated acoustic environments, Method 1 provides only a coarse estimate of localization accuracy and proportion of front/back errors. Method 2 used 36 equally spaced loudspeakers, a sound treated environment, and a chair instrumented with a laser pointer. Performance is compared as a function of separation between loudspeaker pairs in Method 1 and test method. The analyses include measures of bias, magnitude, and whether errors are due to poor acuity or front/back confusion. The utility of the proposed test configurations to assess the effects of headgear on auditory spatial awareness will be discussed.