Terminal progress report, midfrequency dysfunction in noise-exposed persons.
Vanderbilt University, Nashville Tennessee 1982 Jun; :1-38
The effects of noise exposure on midfrequency auditory signal processing were investigated in subjects with high frequency sensorineural hearing loss. Two tone unmasking, psychophysical tuning curves, and pure tone masking patterns were measured at 500 and 1000 Hertz (Hz) in the test subjects and in 20 subjects with normal hearing. Otologic diagnosis of test subjects was that of noise induced hearing loss. Speech understanding ability was measured. Unmasking data for test subjects and comparisons was not informative. In the masking pattern, data obtained at 500 and 1000Hz in 12 of the 17 impaired subjects was essentially normal; 5 were clearly abnormal (more than two consecutive or three total data points outside 99 percent confidence intervals for a masking pattern or tuning curve). In comparisons, hearing thresholds were all within 99 percent confidence intervals. Understanding abilities under quiet and noisy conditions were greatly decreased in test subjects and were most decreased in subjects with midfrequency dysfunction. The author concludes that 29 percent of subjects with high frequency sensorineural hearing loss due to noise exposure also have midfrequency dysfunction. Subjects with midfrequency dysfunction exhibit poorer performance on tests of speech recognition, particularly under noisy conditions, than subjects without midfrequency dysfunction.
NIOSH-Grant; Employee-exposure; Occupational-exposure; Noise-exposure; Exposure-levels; Ear-disorders; Nerve-damage; Industrial-hazards
Final Grant Report
NTIS Accession No.
Vanderbilt University, Nashville Tennessee
Hearing and Speech Sciences Vanderbilt University Div of Hearing & Speech Scis Nashville, Tenn 37232