Directional localization in high ambient noise with and without the use of hearing protectors.

Personal hearing protective devices (HPDs) are becoming increasingly common in settings where levels of noise above 85 dB(A) represent a potential threat to hearing. Several previous studies have indicated that the use of such devices adversely affects the localization of sounds, but none of these experiments employed very precise measures of location discriminability. The major study in the present report examined just such fine discrimination, using a forced-choice task, and compared the effects of three different HPDS. Localization signals were 1.5 s bursts of noise (≥ 1 kHz). Both of the described experiments were conducted in acoustically complex, reverberant environments, to simulate real working conditions. Results indicated that greater attenuation (especially at higher frequencies) was the primary factor associated with poor performance on the fine discrimination task.