Free-field sound localization on the horizontal plane as a function of stimulus level with an electronic, level-dependent hearing protection device

• Published in: The Journal of the Acoustical Society of America 2017-05, Vol.141 (5), p.3636-3636
• Main Authors: Thompson, Eric R., Ennis, Zachariah N.
• Format: Article
• Language: English
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/1.4987835

Electronic, level-dependent hearing protection devices (HPD) provide different levels of attenuation as a function of the input sound pressure level, so that loud sounds are attenuated for protection, but soft and moderate sound levels may be presented with little or no attenuation, or even with a small positive gain. While previous experiments have investigated sound localization with HPDs and moderate stimulus levels, it is important to understand the impact of level-dependent HPDs on the localization of both low- and high-level sounds. In this experiment, horizontal-plane sound localization judgments were obtained from human listeners with and without an earplug-type electronic, level-dependent HPD at several stimulus levels from 20 to 80 dB SPL. The data were analyzed in terms of the proportion of front/back reversals, and the mean absolute lateral error after correcting for front/back reversals. There were very few front/back reversals in the open-ear conditions at any level, and the mean absolute lateral error was less than 5 degrees. With the HPD, there were more front/back reversals than with open ear and the mean lateral error was greater, particularly for the loudest sounds where amplitude compression may have had an influence on performance.