Child voice and noise; acoustic effects of a day at the day-care related to background noise levels

Abstract

Several studies have found that high background noise levels are detrimental to health parameters. In particular, this seems to apply to developing voices were future vocal habits are established. Thus, it is important to study vocal function and environmental effects on the developing child voice. This study analyzed the effects of background noise on children’s voices, specifically vocal intensity, and fundamental frequency. The investigated vocal parameters were (1) the relationship of background noise levels to F0 and vocal intensity, (2) F0 and vocal intensity variations over the day, and (3) F0 perturbation variations over the day. Ten 5-year-old children from three day-cares participated, six boys and four girls. The audio signal was recorded by two microphones mounted in front of the subjects’ ears. By adding these signals it is possible to separate the voice from background noise. The material analyzed contained data from three 60-min recordings per child from morning, noon, and afternoon during a normal day at the day-care. Generally high mean background noise levels were found (82.6 dBA). Preliminary results suggest a correlation between high background noise and high F0 and vocal intensity in the children’s voices, particularly for boys. F0 perturbation tends to increase during the day.