Classroom acoustic measurements and audiological screening of year 1 school children
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Date
2012-06
Authors
Abbood Al-Dulaimi, Saif Hasan
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
Noise is connected to a deteriorating quality of life, by interfering with speech, by accelerating and escalating the development of negative social behaviors such as irritability and neurosis, as well as interferes with attention and consequently performance and productivity. In classrooms the sound perception is obscured by ambient noise and reverberation. Excessive reverberation and ambient noise have a marked negative effect on speech perception by smearing or masking sound. While hearing loss is a common and considerable disability that harms educational performance of school children in developing countries unfortunately, school-aged children are rarely screened for hearing loss during routine clinical examination, and health authorities pay little attention to audiometric evaluation particularly in primary schools. This is usually attributable to the inadequate knowledge of parents, school authorities and healthcare providers on the outcomes of mild hearing loss. Therefore, hearing screening at school entry has been proposed for the early detection and rehabilitation of hearing impaired school children in the developing countries. The main objective of this study was to study the acoustic measurement of the classrooms and the status of hearing among children at entry school age. This study consisted of three parts. The first part of this study was about measuring the sound attenuation of sound treated booths while the second part of this study measured the noise levels and reverberation times in selected classrooms of the schools. The last part of this research was the main part whereby school children were screened for their ear and hearing status. This was
done by choosing two primary schools, a public and a private school. Noise was measured using sound level meter at 5 points in each classroom. Meanwhile the measurement of reverberation time was conducted using Sound Forge software. The data obtained showed that the attenuation values of broadband noise at different intensity levels for the two different sound treated booths were almost similar. The attenuation of pure tones at the lower frequencies (250, 500 and 1000 Hz tones) for the two sound treated booths showed that the UK made sound treated booth having higher attenuation values than the locally made, especially at higher intensity levels. For high frequency tones, the attenuation values for both sound treated booths were almost identical at all intensity levels. For the noise level, in classrooms at the private school is lower than the noise level in classrooms at the public school. Overall, the mean noise level in classrooms at the private school ranges from 52.1 to 67.6 dBA and the mean noise level in classrooms at the public school ranges from 54.8to 76.7 dBA. The mean reverberation time obtained from this study is 0.51± 0.05 seconds in private school and 0.76 ± 0.16 seconds in the public school. For the ear examination and hearing across sectional study was conducted in schools of Kota Bharu, Kelantan. A total of 227 student with a mean age of 6.5years (range 6-7 years) participated in this present study. Both ears were examined using otoscope, DPOAE, tympanometry and pure tone audiometer. Altogether 454 ears were examined, the otoscopical examination showed 101 abnormal right ears and 95 abnormal left ears and the most common finding was ear wax followed by otitis media with effussion . Thirty nine (17.2%) students failed (refer) DPOAE whereby 16(7%) in the right ear and 11(4.8%) left ear while 12(5.2%) were referred in both ears. Tympanometry was abnormal in 66(29%) right ears and
60(26.4%) left ears. The pure tone audiometry (PTA) showed that 113(50.2%) right ears and 125(55.5%) left ears has hearing loss in single frequency. When hearing impairment was examined with PTA the use of four frequencies 31(13.6%) students found to be impaired, 28 of them were mild and 3 moderately impaired. This impairment was bilateral in 14(6.2%) children and 6 (2.6%) in the left ear, 11(4.8) in the right ear. When the validity of DPOAE as a screening tool was examined against the PTA it showed a sensitivity of 95% and the specificity was 59%. In conclusion routine screening based on the identification of ear conditions will facilitate the detection of hearing impaired school-aged children which can be treated early to avoid possible complications and to avoid its impact on behavior and education.
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Keywords
Noise and reverberation