Hearing protection: surpassing the limits to attenuation imposed by the bone-conduction pathways.

  title={Hearing protection: surpassing the limits to attenuation imposed by the bone-conduction pathways.},
  author={Elliott H. Berger and Ronald W. Kieper and Dan Gauger},
  journal={The Journal of the Acoustical Society of America},
  volume={114 4 Pt 1},
With louder and louder weapon systems being developed and military personnel being exposed to steady noise levels approaching and sometimes exceeding 150 dB, a growing interest in greater amounts of hearing protection is evident. When the need for communications is included in the equation, the situation is even more extreme. New initiatives are underway to design improved hearing protection, including active noise reduction (ANR) earplugs and perhaps even active cancellation of head-borne… 

Hearing Protection for Bone-Conducted Sound

The aim of this investigation was to characterise the transmission levels of bypass sound to the cochlea and to determine the effectiveness of different hearing protection components in attenuating this sound.

Sound attenuation from earmuffs and earplugs in combination: maximum benefits vs. missed information.

Sufficient low-frequency attenuation may be achieved with muffs and plugs in combination to prevent hearing loss from operational noise and choose a smaller earplug to achieve a better fit.

Investigating Double Hearing Protection using Human Subjects

From direct measurements of the Sound Pressure Level under the earmuffs during the MIRE procedure, it can be concluded that the attenuation of the earMuff remains constant, implying that there is an interaction between earmuff and earplug that is leading to the degradation of the attenuations afforded by the double protection system.

Effectiveness of hearing protector devices in impulse noise verified with transiently evoked and distortion product otoacoustic emissions

Findings suggest that the HPDs are able to prevent cochlear damage, and both types of OAEs were evaluated in subjects before and after exposure during a five-day military practice.

Proceedings of Meetings on Acoustics

Since introduction in 1972, roll-down slow-recovery foam earplugs have become nearly ubiquitous. They are used widely in industries and by consumers around the world. Their performance has been

Finite Element Modeling and Exploration of Double Hearing Protection Systems

Abstract : Noise levels in modern industrial and military environments are constantly increasing, requiring the improvement of current hearing protection devices. The improvement of passive hearing

Boothless audiometry: Ambient noise considerations

Ambient noise in the test environment will impact signal detection during hearing threshold measurements due to psychoacoustic masking effects. Technical standards specify the maximum permissible

Development and validation of a field microphone-in-real-ear approach for measuring hearing protector attenuation.

The hearing conservationist now has available a portable, convenient, quick, and easy-to-use system that can improve training and motivation of employees, assign hearing protection devices based on noise exposures, and address other management and compliance issues.


Military Operators (MOs) are exposed to a broad range of impulse noise that can vary greatly in terms of level, temporal and spectral characteristics. The accurate characterization of the performance



Laboratory Attenuation of Earmuffs and Earplugs Both Singly and in Combination

For very high-level noise exposures, especially when 8-hour, time-weighted averages are greater than 105 dBA, the attenuation of a single hearing protection device may be inadequate. For such

Is real-ear attenuation at threshold a function of hearing level?

  • E. Berger
  • Physics
    The Journal of the Acoustical Society of America
  • 1985
In the course of measuring the real-ear attenuation at threshold (REAT) of experimenter-inserted E-A-R foam earplugs on 100 subjects, a statistically significant correlation was observed between

Influence of physiological noise and the occlusion effect on the measurement of real-ear attenuation at threshold.

The most commonly alleged experimental artifact associated with real-ear attenuation at threshold (REAT) measurements of hearing protection devices (HPDs) was examined and no evidence was found in the data to suggest a dependency of HPD attenuation on sound level.

In Search of the Bone‐Conduction Threshold in a Free Sound Field

Several investigators have attempted indirect determination of the bone‐conduction threshold in a free sound field. It has recently become possible to attenuate sound transmitted through the auditory

Protection of the ear from noise: Limiting factors

A theoretical and experimental study with this title was undertaken in the 1952–1953 period and published in the Benox Report [‘‘An Exploratory Study of the Biological Effects of Noise,’’ Univ. of

Mechanical parameters of hearing by bone conduction.

A new, powerful, magnetostrictive bone conduction (BC) vibrator is described, which has a wide frequency range, and for midfrequencies undistorted outputs reach up to 50 g in terms of acceleration.

Isolating the auditory system from acoustic noise during functional magnetic resonance imaging: examination of noise conduction through the ear canal, head, and body.

It is estimated that a helmet, earmuffs, and earplugs together will reduce the most intense fMRI noise levels experienced by a subject to 60-65 dB SPL.

Bone and tissue conduction of high intensity acoustic energy to the human cochlea

Noise fields near operating high performance fighter aircraft range from 140 to 150 dB overall sound pressure level. Much of the acoustic energy which is transmitted to the cochlea in a well

The use of acoustical test fixtures for the measurement of hearing protector attenuation. Part II: Modeling the external ear, simulating bone conduction, and comparing test fixture and real-ear data.

A model to estimate HPD-dependent bone conduction effects and explains the occlusion effect of HPDs and the masking error at low frequencies due to physiological noise that arises when real-ear attenuation at threshold (REAT) measurements are made.

Experiments on the Bone‐Conduction Threshold in a Free Sound Field

Earlier investigators of the free‐field bone‐conduction threshold occluded the auditory meatus with plugs and muffs and reasoned by various arguments that the real‐ear attenuation obtained was less