Speech privacy as a harmonizing factor in rating the sound insulation between dwellings
* Presenting author
Recent consulting practice has shown an increase in the number of complaints concerned with insufficient sound isolation between dwellings. In some of them the sound reduction index value was above the value proposed in legislation, but the neighbours’ conversation was heard too clear. Comprehensive analysis has shown that in new buildings there is an extremely low ambient noise level, often below 20 dBA. One can guess that energy efficiency introduced extremely good windows on the facades, and in the same time home appliances and equipment have become too quiet. Such environment enable clear recognition of the neighbours’ speech even with enhanced sound insulation. The conclusion is that in evaluation of sound insulation between dwellings it is suitable to include somehow, besides R or D, the ambient noise level as an embedded factor. A parameter called Speech privacy class as a measure of speech privacy had been introduced in the literature. It is defined as the sum of frequency restricted values of D and ambient noise level. The paper discusses the possibility of introducing such information regarding privacy in assessment of the sound isolation between dwellings. Such approach promises to provide harmonisation of sound insulation assessment and the subjective experience.