Y Wang1, B Yang, Y Li, L Hou, Y Hu, Y Han. 1. Department of Otorhinolaryngology, Hospital of China First Automobile Group Corporation, Changchun 130011, China. likang_qy@faw.com.cn
Abstract
OBJECTIVE: To assess the application of 10-20 kHz audiometry in early diagnosis of noise-induced hearing loss and to explore the relationship between hearing loss and subjects' age, the exposure time as well as the noise level. METHODS: One thousand workers with noise exposure history were examined by pure tone audiometry(0.5-20 kHz). One hundred and twenty normal subjects served as the control group. RESULTS: The noise levels at working sites ranged from 95 to 115dB(A). Compared with the control group, noise-exposed subjects showed minor changes in the thresholds from 0.5 to 6 KHz, whereas the thresholds were elevated in the high frequency range of 10-16 kHz (P < 0.001). The incidence of ears without any response to the maximum output at the frequency range of 14 to 20 kHz was much higher (P < 0.01) than that of the control group. In the animals exposed to noise, the thresholds of 10-18 kHz increased with the aging and with increase of working time (6-10 years), but there were no significant differences among subjects exposed to the noises at different levels(P > 0.05). CONCLUSION: In noise-exposed ears, the occurrence of threshold changes in the high frequency range (10 to 20 kHz) is earlier than that in the low frequency range (0.5 to 6 kHz). Aging and working time also affect the 10-20 kHz hearing thresholds. The lack of responses to maximum output and the changes in thresholds in the high frequency range (10-20 kHz) can be used as indices for the diagnosis of early noise-induced hearing loss and for the assessment of the susceptibility of the subject to noise damage.
OBJECTIVE: To assess the application of 10-20 kHz audiometry in early diagnosis of noise-induced hearing loss and to explore the relationship between hearing loss and subjects' age, the exposure time as well as the noise level. METHODS: One thousand workers with noise exposure history were examined by pure tone audiometry(0.5-20 kHz). One hundred and twenty normal subjects served as the control group. RESULTS: The noise levels at working sites ranged from 95 to 115dB(A). Compared with the control group, noise-exposed subjects showed minor changes in the thresholds from 0.5 to 6 KHz, whereas the thresholds were elevated in the high frequency range of 10-16 kHz (P < 0.001). The incidence of ears without any response to the maximum output at the frequency range of 14 to 20 kHz was much higher (P < 0.01) than that of the control group. In the animals exposed to noise, the thresholds of 10-18 kHz increased with the aging and with increase of working time (6-10 years), but there were no significant differences among subjects exposed to the noises at different levels(P > 0.05). CONCLUSION: In noise-exposed ears, the occurrence of threshold changes in the high frequency range (10 to 20 kHz) is earlier than that in the low frequency range (0.5 to 6 kHz). Aging and working time also affect the 10-20 kHz hearing thresholds. The lack of responses to maximum output and the changes in thresholds in the high frequency range (10-20 kHz) can be used as indices for the diagnosis of early noise-induced hearing loss and for the assessment of the susceptibility of the subject to noise damage.
Authors: Wenjia Wei; Stefanie Heinze; Doris G Gerstner; Sandra M Walser; Dorothee Twardella; Christina Reiter; Veronika Weilnhammer; Carmelo Perez-Alvarez; Thomas Steffens; Caroline E W Herr Journal: Noise Health Date: 2017 Nov-Dec Impact factor: 0.867