Study of the effect of hearing protectors for military noises based on time-frequency analysis by analytic wavelet transform.
Murphy-W; Zhu-X; Kim-J
Inter-Noise 2006. The 35th International Congress and Exposition on Noise Control Engineering, December 3-6, 2006, Honolulu, Hawaii. West Lafayette, IN: International Institute of Noise Control Engineering, 2007 Aug; 4:2318-2327
The current standard method to evaluate performance of hearing protectors is based on steady-state concepts. The practice may not be adequate for high intensity impulsive military noises because the temporal variation of spectral energy is largely ignored. Characterization of a highly transient event requires a time-frequency (T-F) domain signal analysis. This paper summarizes a preliminary study to develop an evaluation method of hearing protectors used for intense military noises based on the analytic wavelet transform (AWT) technique. It is shown that the AWT is an ideal tool as it retains advantages of both the Fourier transform and wavelet transform. New concepts such as the time-frequency transmission loss (TL), level dependent T-F TL, and frequency weighted time history are introduced that can be used to develop an evaluation metric. Related technical challenges are identified and discussed.
Hearing; Hearing-acuity; Hearing-protection; Military-personnel; Noise; Noise-exposure; Noise-frequencies; Noise-induced-hearing-loss; Noise-levels; Noise-protection
William Murphy, Division of Applied Research and Technology Engineering, Physical Hazards Branch, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cincinnati, OH 45226-1998
Inter-Noise 2006. The 35th International Congress and Exposition on Noise Control Engineering, December 3-6, 2006, Honolulu, Hawaii.
University of Cincinnati