Indoor noise level limits for residential areas affected by transportation noise

Noise criteria for buildings are often set on the basis of expected annoyance levels, which in turn may be seen as a function of activity interference, particularly speech or sleep disturbance. The relationships between various physical measures of noise, reported activity interference, annoyance due directly to the activity interference, and overall annoyance are as yet not clear. This paper describes a probabilistic model linking these variables, and presents a preliminary test of the model using a small data set. Houses exposed to road traffic noise and aircraft noise were chosen. At each house, detailed noise measurements were taken simultaneously outside and inside the house, using two real time one-third octave band analyzers. In addition, a member of the household was asked about activity interference around the house, and about overall annoyance. These data permit feasibility tests of the model, which will later be tested on a more extensive data set. If successful, the model will help to identify acoustical insulation requirements for different noise environments, as well as permitting identification of those aspects of outdoor noise which lead to indoor speech interference and annoyance. This in turn is essential information for setting indoor noise criteria.