|Document ID (ISN)||56717|
|ISSN - Serial title
||0002-8894 - American Industrial Hygiene Association Journal
|Convention or series no.
||Stokes J.P., Royster L.H., Pearson R.G., Royster J.D.
||Subjective evaluation of a prototype earmuff exhibiting flat and nonlinear attenuation characteristics
||Feb. 1991, Vol.52, No.2, p.52-60. Illus. 22 ref.
||Subjective user reponses were obtained for a test earmuff exhibiting approximately flat (uniform) attenuation of about 25dB from 500 to 8000Hz for sound pressure levels (SPLs) less than 120dB. At SPLs above 120dB, the test earmuff exhibited nonlinear (level-dependent) attenuation characteristics such that noise reduction increased with increasing sound level. The study population consisted of police officers executing a series of firing programmes during two sequential and identical relays. The study subjects wore either the test earmuff or a comparable conventional earmuff during the first relay, then the alternate protector for the second relay with the order counterbalanced. Results indicated a significant preference for the test earmuff in three comparison areas: comfort, perceived hearing protection, and speech understanding. The study demonstrates that ammunition type and level of noise exposure contributed significantly to a preference in favor of the test earmuff. The subjects who used the quietest of the ammunition types rated the test earmuff significantly better than the remaining subjects with respect to speech understanding.
||hearing protection; noise; gunfire noise; noise control; earmuffs; firearms
||subjective assessment; sound attenuation; speech interference
||D - Periodical articles
|Country / State or Province||USA|
||Noise, hearing and vibration
|Broad subject area(s)