IntroductionA hearing protection device (HPD) is often used as a protective measure in a work environment when the sound levels of that environment cannot be reduced and such levels pose a threat to workers' hearing. An HPD is a safety device worn by individuals to protect their hearing from the harmful effects of sound (Berger, 2003). Many work environments are known to produce high levels of noise, including factories and military operations. Individuals employed in these professions may be required to wear HPD devices to reduce the risk of noise-induced hearing loss. However, some situations in these work environments require the listener to be able to hear even low-level sounds for safety reasons. It is difficult to provide an HPD that attenuates high-level sounds while still allowing low-level sounds to be perceived. In most cases, people must choose between protecting their hearing by losing essential low-level auditory information, or remaining without hearing protection and putting themselves at risk of temporary or permanent noise-induced hearing loss (Brungart & Hobbs, 2007) . Furthermore, the implementation of HPDs can change the temporal and spectral cues of an auditory signal, which can interfere with the ability to detect the direction of a sound source (Bolia et al. 2001). Without location capabilities, an individual is at greater risk of occupational hazards and jeopardizes their own safety and the safety of others. Styles of HPDs and their effects on sound localization will be discussed to provide information to people required to wear hearing protection in high-risk occupations.Types of Hearing Protective DevicesDifferent styles of hearing protection... ... half of the document .... ..the Hygiene Association (AIHA). chap. 10, 379-454. Bolia, R. S., D'Angelo, W. R., Mishler, P. J., & Morris, L. J. (2001). Effects of hearing protectors on auditory localization in azimuth and elevation. Human Factors, 43(1), 122-128. Borg, E., Bergkvist, C., & Bagger-Sjoback, D. (2008). Effect on directional hearing in hunters using amplified hearing protection (depending on level). Otology and Neurotology, 29, 579-585. Brungart, D. S. & Hobbs, B. W. (2007). A comparison of acoustic and psychoacoustic measurements of pass-through hearing protectors, in Proceedings of the 2007 IEEE Workshop on Applications of Signal Processing to Audio and Acoustics, New Paltz, New York. October 21-24, 2007. Simpson, B. D., Bolia, R. S., McKinley, R. L., & Brungart, D. S. (2005). The impact of hearing protection on sound localization and orientation behavior. Human factors, 47(1), 188-198.