Noisiness and Perceived Noise Levels in Some Food Processing Industries in Jos

Abstract

Measurement of noise sound pressure levels in food processing industries, a social survey to determine the extent to which the workers were disturbed by the noise in the same industries, in Jos, were carried out. In all the industries, only one had equivalent continuous noise level below 85dBA. The results of the physical measurements showed that the noise was predominantly broad-band, continuous and steady state. Noisiness and perceived noise levels were obtained from the results of the physical measurements. The result showed that perceived noise levels were not more than 2dB higher than their corresponding equivalent continuous noise levels implying that the human ear perceives noise (2 dB maximally) higher than that measured by a sound level meter on A-weighting scale. For noise levels at 90dB and above small increase would result to higher noisiness increase. However, noise level and perceived noise level have continuous and steady dependence at all values. The correlation coefficient for noise rating and perceived noise level ϒ₁=0.8599, and the correlation coefficient for noise annoyance and perceived noise levels ϒ₁=0.8892, both showing strong positive correlations between objective and subjective assessment of noise.