Korean J Aerosp Environ Med.
2000 Jun;10(2):120-128.
Hearing Threshold Shifts Among Female Communication Workers Wearing
Monaural Headset
- Affiliations
-
- 1Department of Preventive, Medicine, College of Medicine, Hanyang University.
- 2Department of Occupational, Medicine, College of Medicine, Hanyang University.
- 3Department of Otolaryngology, Medicine, College of Medicine, Hanyang University.
- 4Department ofDepartment of Preventive Medicine, College of Medicine, Catholic University.
Abstract
-
BACKGROUND: This study was designed to evaluate the effect of monaural headset to
the hearing threshold shifts of the female communication workers.
METHODS
Hearing threshold shifts of total 642 subjects, selected after excluding workers
with history of ear disease, of ototoxic drug administration, and of neuropsychiatric disease,
were determined by pure tone audiometric tests. Each worker's personal and work history was
taken by the self-administrative questionnaire. In addition, occupational noise exposure
levels in the workplace were assessed by noise dosimetry and each worker's noise exposure
from the headset was measured by placing the microphone of a noise dosimeter to the external
portion of the headset which was coupled by a silicon tube. The hearing threshold shifts were
compared between groups of the alternate and the fixed headset user.
RESULTS
The results were as follows: 1> The noise levels in the workplace ranged
from 62.1 dBA to 63.9 dBA. The mean equivalent sound levels (LEQ) by the headset volume
(minimum, middle, and maximum) were 90.8 dBA, 94.6 dBA, and 97.8 dBA, respectively.
The maximum sound level (Lmax) of the headset was from 109.1 to 128.6 dBA. 2> The degree
of hearing difference of the one side users was higher than that of the alternate users.
Comparing the hearing loss of two groups of subjects, hearing loss was statistically
significantly higher in the left-ear fixed and in the alternate headset users with more
than 15 years than those with less than 15 years of headset taking duration.
3> Based on the hearing loss evaluation criteria by the Korean Ministry of Labor,
25 required follow-up cases (3.89%) and 16 suspected cases (2.49%) out of the 642 subjects
were screened. Although statistically not significant, the required follow-up cases were
higher among fixed users (4.3%) than those of alternate users (3.7%).
CONCLUSION
The results of this study ascertained the possibility of hearing loss due
to monaural-headsets among female workers. Thus, it is recommended that an effective hearing
conservation program should be provided for the headset-wearing communication workers.