This study included three study groups; solvent, noise and mixed, and finally a control group. Each group constituted of 40 subjects with a total of 80 ears per group. Workers in the solvent group are only exposed to organic solvents in their jobs. Similarly workers in the noise group are only exposed to noise and finally those in the mixed group are exposed to both solvent and noise. The control group was neither exposed to organic solvents or noise. Environmental monitoring was performed to assess the noise and solvent levels. Similarly biologic monitoring of hippuric acid was performed to all study groups to detect the presence of organic solvent in the body. All subjects in this study submitted to the following: detailed history (personal and job), urine sample for determination of urinary hippuric acid, otological examination. Pure tone audiometry, speech audiometry, tympanometry and contralateral acoustic reflex thresholds (ART) testing, distortion product otoacoustic (DPOAE) emissions audiogram and Brain-stem auditory evoked potentials were all performed to cochlear function and retrocochlear pathway.