Evaluation of Central Auditory Processing in Individuals with Occupational Noise exposure

Abstract

Abstract Background Prolonged exposure to high levels of occupational noise can cause damage to hair cells in the cochlea and result in permanent noise-induced cochlear hearing loss. Consequences of cochlear hearing loss on speech perception and psychophysical central auditory abilities have been well documented. Objectives the aim of this research was to explore central auditory processing in individuals with history of occupational noise exposure. Subjects and method sixty subjects aged between 20 and 50 years divided into 2 groups; control group (thirty normal healthy subjects), study group (thirty subject with history of occupational noise exposure). They were subjected to Basic audiological evaluation :Pure tone audiometry for frequencies 250-8000 Hz for air conduction and 500-4000 Hz for bone conduction, Speech reception threshold (SRT) using Arabic spondee words list (Soliman et al., 1985) and speech discrimination scores using Arabic phonetically balanced words (Soliman, 1976). And Tympanometry, central auditory processing questionnaire and Psychophysical central auditory tests that will be discussed later. Results Statistically significant difference was found between the study group and control group regarding left Dichotic digits test versionII (p = 0.020), The mean of SPIN either at Right or Left ear for study group was depressed in comparison to normal individuals, those differences were statistically highly significant (p < 0.001). Furthermore, there was a Highly statically significant difference in TCST (30%,60%), GIN test and DPT between study and control groups (p < 0.001) either at Right or Left ear. Conclusions Patients with occupational noise exposure had poor performance in all central auditory tests when compared with control. This means that occupational noise exposure can lead to impaired central auditory processing with subsequent in adults