ANSI/ASA S3.71:2019

The methods described in this standard were designed to enable accurate, repeatable, and reliable measurement of sound localization performance with or without head-worn devices. The standard is based on fundamental localization measurement paradigms that have been used in numerous laboratories. Three measurement methods are described. Method 1 should be viewed as a simplified procedure for estimating localization performance. Method 2 should be used as a robust measure of localization performance with or without head-worn devices and should identify moderate to significant degradation of localization cues. Method 3 should be used as a measure of the functional impact of degraded localization cues. Each of the methods captures differing aspects of localization performance and the effects of degraded localization cues from head-worn devices. Data from measurements detailed in this standard can be used to describe the effects of head-worn devices on localization in the horizontal plane and can be used to assess the relative performance of subjects wearing head-worn devices compared to open-ear localization performance. Users of this standard include universities, manufacturers of hearing devices (e.g., hearing protectors, communication headsets, hearing enhancement with ambient listening capability, hearing aids), commercial test laboratories, and government laboratories.
The methods described in this standard are limited to measurements of human localization performance in the horizontal plane (azimuth) only and are not intended to be used for clinical spatial audiometry or for measuring localization performance in elevation. The methods are not intended to be used for measurement of sound localization performance of devices designed to determine the location of acoustic sources.
NOTE 1 Method 1 was intentionally designed to be relatively limited in sophistication to make it more accessible to users of the standard without requiring the resources necessary for using Methods 2 and 3.
NOTE 2 Auditory localization may improve over time for individuals who wear hearing protection or other head-worn devices more than occasionally. The localization results obtained using the methods described in this standard are intended to assess localization performance before auditory learning with a specific device has occurred over a period of hours or days. For additional guidance see 4.1.6.2, 4.1.6.3, and 8.1.