Socio-Acoustic Survey of Sound Quality in Dwellings in Norway

An extensive socio-acoustic survey has been performed in Norway. Based on field measurements of sound insulation in 600 dwellings, a questionnaire survey was sent to the residents. 986 respondents evaluated the sound quality of their homes, 97% of which were apartments in multi-unit houses. The field measurements showed a relatively wide range of variation in the results, even though all dwellings are fairly new, and supposed to be built in accordance with today's requirements. The range in the measurement results allowed us to establish exposure-effect relationships for annoyance for both impact and airborne sound insulation. The correlation between subjective evaluation and measured sound insulation descriptors showed interesting variations. For airborne sound insulation the standardized level difference DnT,w showed the best correlation in most cases; the low-frequency spectrum adaptation term (including 50 Hz) did not improve the correlation except in relation to music with bass and drums. However, for impact sound the results were strongly in favor of the low-frequency spectrum adaptation term (including 50 Hz); without this there was no correlation with subjective response. The outcome of the project give grounds for choosing sound insulation limits based on annoyance.