Noise-induced hearing loss (NIHL) is a serious problem in occupational environments; however, there is little information about hearing loss due to combined exposure to noise and vibration. This study aimed to investigate the combined effects of exposure to noise and whole-body vibration (WBV) on hearing responses under simulated heavy equipment driving conditions. A repeated measures study was designed to evaluate the changes in distortion product otoacoustic emissions (DPOAE) amplitudes as hearing responses to 40 min of noise and/or WBV exposure. Thirty healthy males with an average age of 30.17 (±3.94) years, exposed to noise level of 85 dB(A) and two WBV levels (0.87 and 1.3 m/s²) in six experimental scenarios. The findings revealed that there was a significant change in DPOAE amplitudes after single noise exposure and combined noise and WBV exposure (p < 0.05); however, there was no significant difference in WBV exposure alone (p > 0.05). The changes in DPOAE amplitudes were greater in combined exposure to noise and WBV (1.3 m/s²) in all sessions. The statistical analysis showed the effect sizes of the combined exposure to noise and WBV were more than the sum of the exposure to each one alone. It can be concluded that some synergic effects can occur in DPOAE amplitudes in the combined noise and WBV exposure under heavy equipment driving conditions. These findings can help the occupational health experts adapt the existing physical agents' exposure limits to the realistic conditions of the occupational settings.

噪声引起的听力损失（NIHL）在职业环境中是一个严重的问题。然而，由于噪声和振动的共同作用，关于听力损失的信息很少。这项研究旨在研究在重型设备模拟驾驶条件下，暴露于噪声和全身振动（WBV）对听力反应的综合影响。设计了一项重复措施研究，以评估失真产物耳声发射（DPOAE）幅度随40分钟的噪音和/或WBV暴露而产生的听力反应的变化。30名健康男性，平均年龄为30.17（±3.94）岁，暴露于85 dB（A）的噪声水平和两个WBV级别（0.87和1.3 m / s ^2））在六个实验方案中。研究结果表明，单次噪声暴露以及联合噪声和WBV暴露后，DPOAE幅度有显着变化（p <0.05）；然而，单独的WBV暴露没有显着差异（p> 0.05）。暴露于噪声和WBV（1.3 m / s ²）在所有会话中。统计分析表明，噪声和WBV的总暴露量大于单独暴露的总和。可以得出结论，在重型设备行驶条件下，DPOAE振幅在组合噪声和WBV暴露下可能会产生一些协同效应。这些发现可以帮助职业健康专家使现有物理代理商的接触限值适应职业环境的实际条件。