Estimated dose-response relationship between impulse noise exposure and temporary threshold shift in tactical...

Area of Science:

• Occupational health
• Auditory science
• Acoustics

Background:

• Impulse noise and blast exposure are occupational hazards for military and law enforcement.
• The impact of these exposures on hearing is not fully understood.
• Understanding hearing damage risk is crucial for protecting personnel.

Purpose of the Study:

• To evaluate hearing changes in service members after tactical exercises.
• To assess the accuracy of different noise metrics in predicting temporary threshold shifts (TTSs).
• To establish a dose-response relationship for impulse noise exposure and hearing risk.

Main Methods:

• Conducted field hearing evaluations on 214 service members using boothless audiometers.
• Measured impulse noise from weapons systems using wearable dosimeters.
• Analyzed impulse waveforms and noise metrics (LAeq,8h, kurtosis, peak sound level, AHAAH model) to predict TTS events.

Main Results:

• LAeq,8h predicted TTS events with 64% accuracy (AUC=0.70), improved to 66% (AUC=0.75) with kurtosis.
• Peak sound level and the Auditory Hazard Assessment Algorithm for Humans (AHAAH) model were less accurate predictors.
• A dose-response relationship showed increased TTS likelihood with higher cumulative noise exposure.

Conclusions:

• Energy-based auditory risk criteria (e.g., LAeq,8h) are supported for impulse noise assessment.
• Further validation is required to quantify the risk of short- and long-term hearing damage from impulse noise.
• Accurate prediction of TTS is essential for developing effective hearing protection strategies.