Analysis of clinical audiological characteristics of noise-induced silent hearing loss

Abstract

Objective: To explore the characteristics of audiology examination of Noise-Induced Hidden Hearing Loss (NIHHL), and then explore its valuable diagnostic methods.

Methods: A total of 80 young men aged between 19 and 35 were selected. They were classified into the experimental group with noise exposure history and the control group without noise exposure history, with 40 men in each group. We carried out extended high-frequency audiometry test for good ears; conducted speech in noise measurement and distortion product emission for good ears; DPOAE test, compare and analyze the results of each test.

Results: The extended high frequency hearing threshold test results showed that the hearing threshold of the experimental group was larger than that of the control group at the frequency above 8kHz, with significant statistical difference (p < .01). The results of speech audiometry under noise showed that the signal-to-noise ratio loss in the experimental group was greater than that in the control group, with a significant statistical difference (p < .01). The results of otoacoustic emission showed that the signal-to-noise ratio of the experimental group was lower than that of the control group at the frequency of 6 kHz and above, with a statistically significant difference (p < .01). There is a correlation between pure tone audiometry and DPOAE test results at high frequencies (6 kHz: p <. 0001, r = -.478; 8 kHz: p < .0001, r = -.491;) ; There was a correlation between speech audiometry and DPOAE test results under noise (p = .031, r = -.299).

Conclusion: Compared with the control group, the extended high frequency pure tone hearing threshold increased or could not be elicited in the experimental group, speech recognition ability decreased significantly under noise, DPOAE was normally elicited but signal-to-noise ratio decreased, and there was a certain correlation between them. The above three audiological examination methods have a certain reference value for early recognition of hidden hearing loss.