Modeling Metabolic Exhaustion of the Auditory System

Abstract

This report describes the results of the two-year project sponsored by the US Army Medical Research and Development Command (USAMRDC) to develop a metabolic exhaustion (ME) model of the auditory system to account for the effect of complex noise exposures on dose accumulation for the development of auditory damage risk criteria. Using chinchilla auditory temporary threshold shift (TTS) data from exposure to complex noise, a ME model was developed that predicts the effects of complex noise exposure on TTS. The complex impulse noise was composed of multiple impulses of unequal intensities and unequal inter-pulse intervals(IPI), and in some cases including the presence of high-intensity background noise. The chinchilla ME model was validated with data comparison and provided an understanding of the mechanism of injury by damage accumulation inside the cochlea. The chinchilla model was adapted to construct the human ME model using cochlear tissue stiffness data measured from chinchilla and human cadaver ears. The ME model is based on a mechanistic description of the energy deficit occurring within the outer hair cells (OHC) inside the cochlea as a result of complex noise exposure. The straining energy of the OHC caused by the noise exposure exceeding a threshold leads to increase in metabolic demand while supply is insufficient that can cause damage. An electroacoustic model of the cochlea including the OHC was developed that calculates the OHC energy deficit (OHC-ED) as the integrated difference between the rate of work of stress within the OHC and available power supply. The OHC-ED was correlated to TTS data to establish the dose-response curve for complex noise exposure. The major findings of this study are summarized as follows. There was a good correlation between the OHC-ED predictions and TTS data from chinchillas. The dose-response curve was established with a good fit and relative tight confidence band, considering the small data sample size.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 2019
Accession Number
AD1111979

Entities

People

  • B Zagadou
  • K Ho
  • Philemon Chan

Tags

Communities of Interest

  • Biomedical
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Algorithms
  • Background Noise
  • Biological Sciences
  • Blast
  • Computer Programs
  • Data Analysis
  • Ear
  • Frequency
  • Information Science
  • Measurement
  • Medical Personnel
  • Membranes
  • Pressure Measurement
  • Regression Analysis
  • Sound Pressure
  • Statistical Analysis
  • Time Intervals

Readers

  • Auditory Neuroscience/Auditory Physiology.
  • Computational Modeling and Simulation