Signal detection and speech perception with level-dependent hearing protectors.
An experiment was conducted to investigate signal detection and speech perception with level-dependent hearing protectors. Twenty normal-hearing young adults participated in the first phase of this program, the ultimate objective of which was an assessment of the effect of hearing loss. For each subject, measurements were made of the detection of one-third octave noise bands centered at 500, 1000, 2000 and 4000 Hz, consonant discrimination, and word recognition. Performance on these tests was evaluated in quiet and in a background of 75 dB SPL cable swager noise, with the ears unoccluded and protected with four different muffs. The devices selected were the E-A-R 9000 and BILSOM 2390 and their conventional level-independent counterparts, the E-A-R 3000 and BILSOM 2315. The results indicated that signal detection in noise generally remained the same or was slightly enhanced when the protectors were worn. For consonant discrimination, there were no differences among the various protectors in quiet, while in noise the wearing of the BILSOM 2390 resulted in a significant decrement in the intelligibility of the initial consonant. For word recognition, the BILSOM 2390 resulted in an advantage in quiet, particularly for sentences with low contextual cues. The reverse effect was true in noise. The results obtained for the E-A-R 9000 were similar to those for the two conventional HPDs.
Abel
S M
SM
Department of Otolaryngology, Mount Sinai Hospital, Toronto, Ontario, Canada.
Krever
E M
EM
Giguere
C
C
Alberti
P W
PW
D000162:Acoustics; D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001302:Audiometry, Speech; D001309:Auditory Threshold; D004430:Ear Protective Devices; D006801:Humans; D009622:Noise; D013067:Speech Perception