Fuente Adrian, McPherson Bradley
Centre for Communication Disorders, The University of Hong Kong, Hong Kong.
Int J Occup Med Environ Health. 2007;20(3):271-9. doi: 10.2478/v10001-007-0030-4.
Various studies have demonstrated that organic solvent exposure may induce auditory damage. Studies conducted in workers occupationally exposed to solvents suggest, on the one hand, poorer hearing thresholds than in matched non-exposed workers, and on the other hand, central auditory damage due to solvent exposure. Taking into account the potential auditory damage induced by solvent exposure due to the neurotoxic properties of such substances, the present research aimed at studying the possible auditory processing disorder (APD), and possible hearing difficulties in daily life listening situations that solvent-exposed workers may acquire.
Fifty workers exposed to a mixture of organic solvents (xylene, toluene, methyl ethyl ketone) and 50 non-exposed workers matched by age, gender and education were assessed. Only subjects with no history of ear infections, high blood pressure, kidney failure, metabolic and neurological diseases, or alcoholism were selected. The subjects had either normal hearing or sensorineural hearing loss, and normal tympanometric results. Hearing-in-noise (HINT), dichotic digit (DD), filtered speech (FS), pitch pattern sequence (PPS), and random gap detection (RGD) tests were carried out in the exposed and non-exposed groups. A self-report inventory of each subject's performance in daily life listening situations, the Amsterdam Inventory for Auditory Disability and Handicap, was also administered.
Significant threshold differences between exposed and non-exposed workers were found at some of the hearing test frequencies, for both ears. However, exposed workers still presented normal hearing thresholds as a group (equal or better than 20 dB HL). Also, for the HINT, DD, PPS, FS and RGD tests, non-exposed workers obtained better results than exposed workers. Finally, solvent-exposed workers reported significantly more hearing complaints in daily life listening situations than non-exposed workers.
It is concluded that subjects exposed to solvents may acquire an APD and thus the sole use of pure-tone audiometry is insufficient to assess hearing in solvent-exposed populations.
多项研究表明，接触有机溶剂可能会导致听觉损伤。针对职业性接触溶剂的工人开展的研究表明，一方面，他们的听力阈值比相匹配的未接触工人更差，另一方面，溶剂接触会导致中枢听觉损伤。鉴于此类物质的神经毒性特性，溶剂接触可能会引发潜在的听觉损伤，本研究旨在探究接触溶剂的工人可能出现的听觉加工障碍（APD）以及在日常生活听力环境中可能存在的听力困难。
对50名接触有机溶剂混合物（二甲苯、甲苯、甲乙酮）的工人以及50名年龄、性别和教育程度相匹配的未接触工人进行了评估。仅选取无耳部感染、高血压、肾衰竭、代谢及神经疾病或酗酒史的受试者。这些受试者听力正常或患有感音神经性听力损失，且鼓室图结果正常。对接触组和未接触组进行了噪声中听力（HINT）、双耳数字（DD）、滤波言语（FS）、音调模式序列（PPS）和随机间隙检测（RGD）测试。还对每位受试者在日常生活听力环境中的表现进行了自我报告清单评估，即阿姆斯特丹听觉残疾和障碍清单。
在某些听力测试频率上，发现接触组和未接触组工人的双耳阈值存在显著差异。然而，总体而言，接触组工人的听力阈值仍属正常（等于或优于20 dB HL）。此外，在HINT、DD、PPS、FS和RGD测试中，未接触组工人的成绩优于接触组工人。最后，接触溶剂的工人在日常生活听力环境中报告的听力问题明显多于未接触组工人。
得出的结论是，接触溶剂的受试者可能会出现听觉加工障碍，因此仅使用纯音听力测定法不足以评估接触溶剂人群的听力情况。
