The variation of environmental noise outside six dwellings between three seasons

Measurements of environmental noise have been made at six sites for one-week periods in three seasons. The noise levels, expressed in six different indices, were shown to be highly correlated with each other. The ways in which the noise levels varied from day-to-day and season-to-season are discussed and at some sites the seasonal changes are shown to be significantly greater than the day-to-day changes. It is also shown that noise levels at quiet sites are more variable than at noisy sites. The implications of variability in noise levels on survey work are discussed, and it is concluded that the variability may be large enough to significantly affect the residual variance unless sites are successfully selected.