Impulse noise injury prediction based on the cochlear energy

Area of Science:

• Audiology
• Biomedical Engineering
• Occupational Health

Background:

• Current impulse noise criteria lack objective hearing protection measures.
• Existing models like AHAAH exhibit anomalous dose-response behavior.
• Impulse noise poses significant risks for hearing injury.

Purpose of the Study:

• Develop a biomechanically-based model for impulse noise injury risk assessment.
• Improve the Auditory Hazard Assessment Algorithm for the Human (AHAAH) using integrated cochlear energy (ICE).
• Establish a reliable damage risk correlate (DRC) for impulse noise exposure.

Main Methods:

• Enhanced the AHAAH model using updated literature data and integrated cochlear energy (ICE) as the damage risk correlate (DRC).
• Investigated and corrected model parameters, particularly annular ligament (AL) compliance, to eliminate dose-response inversion.
• Developed a dose-response curve using human temporary threshold shift (TTS) data and validated against German rifle noise tests.

Main Results:

• The revised AHAAH model successfully eliminated anomalous dose-response inversion by adjusting AL compliance.
• Transfer functions from the new model align well with human ear responses.
• Integrated cochlear energy (ICE) demonstrated excellent correlation with noise-induced hearing injury outcomes for various weapon types.

Conclusions:

• The new AHAAH model utilizing ICE as the dose metric provides an objective measure for hearing protection against impulse noise.
• ICE is identified as the optimal DRC for assessing noise injury from both small and large arms.
• The model is suitable for adoption as a medical standard for impulse noise injury prevention.