Determination of the probability of hearing loss in persons exposed to the noise of small arms

Abstract

Aim to analyze the indicators of distortion-product otoacoustic emissions (DPOAE) in persons exposed to the noise of small arms and, on the basis of the most significant of them, to determine the probability of developing hearing loss.
 Material and methods. We examined 30 male volunteer shooters (60 ears) aged from 19 to 30 years. The shooters fired 30 shots from the AK74M in short bursts (2-3 shots in a burst) at targets when performing shooting exercises from three positions: from the knee, standing and lying down, in a free acoustic field without the use of personal protective equipment of the hearing organ. All participants were examined for distortion-product otoacoustic emissions (DPOAE) before and after firing from small arms. The method of binary logistic regression was used to develop a predictive model.
 Results. A mathematical model has been developed to assess the probability of developing hearing loss according to the indicators of DPOAE before exposure to the noise of small arms. This model, with a standard classification threshold of p = 0.5, has an accuracy of 83.3%, sensitivity of 79.0%, specificity of 88.0%. According to the results of the ROC analysis for the resulting model, the area under the characteristic curve was equal to 0.924 (0.834;1.0), which indicates the excellent quality of the mathematical model.
 Conclusion. The most significant were the signal/noise indicator (dB) at a frequency of 4.2 kHz on the left and the level of otoacoustic emission (dB) at a frequency of 4.2 kHz on the left before noise exposure. These indicators, as well as the age of the shooter, allow us to assess the probability of developing hearing loss.