Method for testing acoustical attenuation of hearing protectors
First Claim
1. A method of measuring, in the presence of significant ambient noise, the acoustical attenuation effectiveness of a hearing protector worn in operative association with an ear by a subject individual, said method comprising the steps of:
- a. generating a variable-amplitude audio signal and a separate audio signal of a constant amplitude sufficiently great to be audible to said individual over said ambient noise;
b. exposing said ear to one of said signals with said hearing protector worn in association with said ear, and without said hearing protector being so worn, respectively;
c. during the exposure of said ear to said signal, exposing the other ear of said individual to the other of said audio signals;
d. varying said variable signal both with and without said hearing protector being so worn until obtaining in each instance an indication from said individual that he perceives that said variable signal has a predetermined common relationship to said constant-amplitude signal; and
e. measuring the difference between the respective amplitudes of said variable signal which are indicated in each instance by said individual as having said predetermined relationship to said constant-amplitude signal.
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Accused Products
Abstract
A method for rapidly and accurately measuring the acoustical attenuation effectiveness of various personal hearing protection devices as worn, particularly in-the-ear type protectors under conditions of normal fit in a working environment having significant ambient noise. The method comprises presenting an audio signal to an ear both with and without the hearing protector in place and noting the difference in intensity of the applied signal, measured in decibels, required to obtain the same perceived amplitude level in each case. The perceived amplitude level may be either the threshold of the subject'"'"'s hearing perception or a supra-threshold reference point determined by a comparison of the test ear signal with a reference signal in the contralateral ear to allow for testing in ambient noise levels of high or fluctuating intensity. The test signal is preferably a multi-frequency complex signal having a preweighted power spectrum which emphasizes those frequencies which are particularly hazardous. The preferred supra-threshold test utilizes a reference signal in the non-test ear which is audibly distinguishable from the signals applied to the test ear other than with respect to amplitude.
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Citations
5 Claims
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1. A method of measuring, in the presence of significant ambient noise, the acoustical attenuation effectiveness of a hearing protector worn in operative association with an ear by a subject individual, said method comprising the steps of:
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a. generating a variable-amplitude audio signal and a separate audio signal of a constant amplitude sufficiently great to be audible to said individual over said ambient noise; b. exposing said ear to one of said signals with said hearing protector worn in association with said ear, and without said hearing protector being so worn, respectively; c. during the exposure of said ear to said signal, exposing the other ear of said individual to the other of said audio signals; d. varying said variable signal both with and without said hearing protector being so worn until obtaining in each instance an indication from said individual that he perceives that said variable signal has a predetermined common relationship to said constant-amplitude signal; and e. measuring the difference between the respective amplitudes of said variable signal which are indicated in each instance by said individual as having said predetermined relationship to said constant-amplitude signal. - View Dependent Claims (2, 3, 4, 5)
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Specification