Temporal aspects of airborne sound insulation and how it affects the subjective estimation
Reinhard O. Neubauer and Jian Kang
Standardised methods exist for measuring the sound insulation of a partition wall or a ceiling. A number of indexes have been defined; each offers various benefits for different situations. All have, however, in common that they have to be obtained using a steady-state sound signal, usually pink noise, and compared against a reference curve as defined in ISO 717-1. This procedure results in a single number rating yielding a sound insulation index. Sound insulation, however, is supposed to protect people’s well-being and health, mentally and physically, in real life situations. Since the currently used descriptors are based on steadystate signals, this paper aims to show the effect using non-steady-state signals in describing airborne sound insulation. For this reason, a comparison is made between using conventional broadband noise signals, including pink or white noise, and using music signals, including classic and rap music. Some indices commonly used to describe airborne sound insulation are discussed and consequently, comparisons with subjectively judged values of airborne sound insulation are made. Some psychoacoustic predictors have also been considered, examining the impact of temporal fluctuating signals to the resulting sound insulation. In the presentation some preliminary results will be presented on this on-going study.