Speech levels and speech-to-noise ratios.

This investigation was concerned with the speech levels of both teachers and pupils in schools for the deaf and in units for partially-hearing children (PHUs) and with the levels of background noise found in these establishments. Twelve classes in 5 schools for the deaf and 8 PHUs were included in this study. The average speech level of the teachers, measured at 2 metres distance, was 57.5 dBA (range, 40-70 dBA) and that of the pupils was 52.9 dBA (range, 45-67 dBA). The levels of background noise measured were unacceptably high varying from 44.6 dBA (average level of quasi-stationary noise) to 76.5 dBA (average level of short-duration noise). It was concluded that the acoustic environments prevailing in these schools and units were not conducive to good hearing aid use and suggestions for improvements were put forward.