The Effects of Recreational Noise Exposure on the Auditory System in Young Adults in Medical School in Nairobi, Kenya.

Abstract

Introduction Exposure to hazardous noise levels can lead to hearing related problems like noise induced hearing threshold shifts (NITS), tinnitus and noise sensitivity. Recreational noise is on the rise and young adults are increasingly exposing themselves to dangerous sound levels from recreational activities. Noise induced hearing loss is permanent. Health-orientated behaviour of young adults might be linked to their attitudes toward noise and hearing loss. We do not have any data in Kenya on recreational noise sources nor their auditory effects. Objectives The objective of the study was to examine the effect of recreational noise exposure on the auditory system of young adults (18-35 years) in The University of Nairobi medical school. Methodology This was a cross sectional study performed in the ENT department of KNH of young adults in medical school aged 18-35 years. Subjects were recruited via convenient sampling after which they completed a recreational hearing habits questionnaire. Hearing was evaluated using Pure Tone Audiometry and Distortional Product Oto Acoustic Emissions. Data analysis was conducted using SPSS version 18. During the initial descriptive analysis each variable in the database was analysed, in turn. For continuous data including age, mean and standard deviation was calculated. Frequency distribution was used to summarize the categorical variables Results Subjects recruited and evaluated were 163 in number with a mean age of 24.6 years and a M:F sex ratio of 1.04:1. The highest weekly noise exposure in equivalent SPLs was found for going to night clubs (82.9 dBA). The median weekly equivalent noise exposure for all activities was 67.7 dBA. 15.3% of subjects exceeded the Environmental Protection Agency limit of 75 dBA. After noise exposure, 58.6% experienced self-reported ear complaints. With regards to the DPOAE, the 5000Hz frequency band recorded referrals of above 30.7%.

The crude prevalence rate of hearing loss was 6.1%. There was no statistical difference in hearing loss between groups with intermediate and high noise exposure. Conclusions The median weekly noise exposure levels produced self-reported hearing complaints and suggestions of sub-clinical hearing loss. However, there was no statistically significant clinical hearing loss experienced by the cohort. Longitudinal studies are required to follow cohorts to ascertain if sub-clinical hearing loss progresses to clinical hearing loss.