Characterization of acute hearing changes in United States military populations.

Until recently, most hearing conservation programs, including those in the military, have used permanent shifts in the pure-tone audiometric threshold as the gold standard for measuring hearing impairment in noise-exposed populations. However, recent results from animal studies suggest that high-level noise exposures can cause the permanent destruction of synapses between the inner hair cells and auditory nerve fibers, even in cases where pure-tone audiometric thresholds eventually return to their normal pre-exposure baselines. This has created a dilemma for researchers, who are now increasingly interested in studying the long-term effects that temporary hearing shifts might have on hearing function, but are also concerned about the ethical considerations of exposing human listeners to high levels of noise for research purposes.

Comparison of Two-Talker Attention Decoding from EEG with Nonlinear Neural Networks and Linear Methods.

Auditory attention decoding (AAD) through a brain-computer interface has had a flowering of developments since it was first introduced by Mesgarani and Chang (2012) using electrocorticograph recordings. AAD has been pursued for its potential application to hearing-aid design in which an attention-guided algorithm selects, from multiple competing acoustic sources, which should be enhanced for the listener and which should be suppressed. Traditionally, researchers have separated the AAD problem into two stages: reconstruction of a representation of the attended audio from neural signals, followed by determining the similarity between the candidate audio streams and the reconstruction.

The Effect of Hearing-Protection Devices on Auditory Situational Awareness and Listening Effort.

Objectives: Hearing-protection devices (HPDs) are made available, and often are required, for industrial use as well as military training exercises and operational duties. However, these devices often are disliked, and consequently not worn, in part because they compromise situational awareness through reduced sound detection and localization performance as well as degraded speech intelligibility. In this study, we carried out a series of tests, involving normal-hearing subjects and multiple background-noise conditions, designed to evaluate the performance of four HPDs in terms of their modifications of auditory-detection thresholds, sound-localization accuracy, and speech intelligibility.

In-ear and on-body measurements of impulse-noise exposure.

Accurate quantification of noise exposure in military environments is challenging due to movement of listeners and noise sources, spectral and temporal noise characteristics, and varied use of hearing protection. This study evaluates a wearable recording device designed to measure on-body and in-ear noise exposure, specifically in an environment with significant impulse noise resulting from firearms. A commercial audio recorder was augmented to obtain simultaneous measurements inside the ear canal behind an integrated hearing protector, and near the outer ear.

Noise dosimetry for tactical environments.

Noise exposure and the subsequent hearing loss are well documented aspects of military life. Numerous studies have indicated high rates of noise-induced hearing injury (NIHI) in active-duty service men and women, and recent statistics from the U.S.