A portable method for ensuring sound protection is … well, sound

For people that spend a lot of time in noisy environments, hearing protection devices (HPDs) are essential to prevent noise-induced hearing loss. Hearing protector fit testing (HPFT) systems measure the effectiveness of HPDs on individuals, but the method is limited: Many commercially available systems can only be applied to HPDs seated in the ear canal, i.e., earplugs, even though many individuals rely on earmuffs or a combination of the two for adequate protection from noise hazards.

Voelker et al. sought a better solution. With a combination of experiments, they wanted to determine whether headphones placed around an individual’s neck, rather than over the ears, can be used as the sound source for portable HPFT systems, and if it can determine an individual’s personal attenuation rating (PAR) — how much HPDs reduce sound.

“Hearing protection fit testing has long been considered a best practice in hearing conservation,” said author Julianna Voelker. “However, the widespread adoption of fit testing has been slow, at least in part because of the limitations on the type of hearing protection devices that can be tested with current commercial fit-test systems.”

The researchers conducted two related experiments. First, they confirmed that the difference in magnitude between on-ear and on-neck sound presentations is relatively constant across headphone placement and variations between individuals’ head and ear geometries. Then, they checked whether PAR calculated using this method is consistent with gold-standard HPFT paradigms, like a field microphone-in-real-ear method.

Overall, there was good agreement between their neck-based HPFT system and standard methods.

Because exposure to hazardous noise environments with inadequate protection can lead to permanent shifts in hearing, the authors hope their method will make HPFT available to all styles of HPDs. This will ensure that performance verification can occur and that individuals who use HPDs will know their level of protection is sound.

Source: “Electroacoustic validation of a neck-based field attenuation estimation system,” by Julianna R. Voelker, Devon Kulinski, and Douglas S. Brungart, Journal of the Acoustical Society of America (2026). The article can be accessed at https://doi.org/10.1121/10.0042977 .