DETERMINATION OF NOISE LEVELS, PERCEPTION AND AUDITORY EFFECT AMONG STUDENTS IN SELECTED PUBLIC SECONDARY SCHOOLS IN IBADAN, NIGERIA

Abstract

Children of school age are considered to be among the group most vulnerable to the adverse effects of noise. Most schools in Nigeria face adverse environmental conditions including, noise and its related impact is poorly documented. This study assessed the ambient noise levels in schools, determined the prevalence of hearing impairment and documented students' perception of noise in their learning environment. The study was a descriptive cross-sectional survey. Three schools were purposively selected within different high activity areas in Ibadan viz: Methodist Grammar School (MGS) Bodija (Market area). Anglican Grammar school (AGS), Total Garden (Traffic area) and (Oke-Bola Comprehensive High school (OBCHS) Oke-Bola (Industrial area). Abadina College (AC) University of Ibadan (Academic area) was selected as the control. A systematic random sampling technique was used to select 300 participants from senior secondary classes. A validated song-structured questionnaire was used to elicit information on their perception of noise, while a calibrated noise level meter was used to measure noise levels in four different locations in each school for one month. Pure-tone audiometry test at standard frequencies was conducted on the exposed and control groups. The observed noise levels and audiometric outcomes were compared with WHO limits. Data were analyzed using descriptive statistics, ANOVA and Chi-square test. The respondents' age ranged between 15-19 years and the mean age was 15.6±0.7 years; and 55.7% were females. Most of the respondents (89.3%) Were aware of the adverse effects of noise. Majority, 87.0% admitted that loud noise could result in hearing loss. Most (98.7%) reported that not was capable of affecting their is performance. Majority of respondents from AGS (80%) and MGS (86%) reported headache as the most severe noise related non-auditory effect compared with the control (26.7%) (p<0.05), while 64% of respondents in OBCHS reported tiredness as the most severe noise related non-auditory effect compared to 41.3% in the control. The range of noise level in the exposed (65.4 dBA-82.1 dBA) and control (58.5 dBA-71.3 dBA) groups exceeded the WHO recommended limits for school environments (35 dBA). The mean noise level for the specific exposed groups include 73.8±5.1 (dBA (AGS), 76.0±18.0 dBA (MGS). and 70.8±8.5 dBA (OBCHS) compared to the control of 63.8±5.3 dBA (p<0.05). The prevalence or hearing impairment at ≥41 dBA in the better car among the participants in the market (MGS) and traffic (AGS) are were 20,0% each and 10.0% in the industrial area (OBCHS) compared to 0.0% in the control area (AC) (p<0.05). High noise levels and hearing impairment were more pronounced among the participants from the major noise generating areas. There is need for Oyo State Government to formulate specific policy guidelines on land use requirement aimed at preventing vulnerable groups especially school children from being exposed to hazardous noise levels.