Speech communication in outdoor soundscapes

The Positive Soundscape Project is a large multi-disciplinary \nproject investigating the perception of soundscapes. Recent \nfindings indicate that speech communication is a principal \nfactor in users’ perceptions of urban soundscapes. The \nproject has therefore explored how this factor might be \nquantified. This paper reports on an attempt to use speech \nintelligibility index (SII) to characterise time-varying speech \nintelligibility in real outdoor soundscapes. The relationships \nbetween SII, subjective intelligibility and subjective quality \nwere explored, as functions of signal-to-noise ratio. Possible \napplications in sound quality mapping of soundscapes and \npotential implications for rational planning of soundscapes \nare discussed.