Experimental studies on annoyance caused by noises from trams and buses

Acute annoyance due to noise from trams and buses was ascertained and compared in two experimental studies. First, 22 healthy young persons (19–22 years) using a standardised scale, rated their annoyance caused by noise from trams, buses and trucks, which were each presented at seven sound levels. The noise of a tram was judged to be equally annoying as the noise of a bus with a 3 dB lower level, which corresponds to the calculated loudness difference. The noises of a tram and of a bus were superimposed onto a 2-h realistic road traffic scenario in the second study. This study was conducted with 60 healthy young persons (18–31 years). Twenty participants were each exposed either to the scenario with the tram or the bus (LAeqT=55 dBA) or to a control condition (LAeqT=43.6 dBA) while working on different mental tasks. Performance data did not differentiate between the noise conditions, but the participants were again less annoyed by the scenario with the tram, suggesting a possible bonus for the tram. This assumption has to be verified in future studies. The fact that calculated loudness could predict annoyance in the psychoacoustic tests and this annoyance due to the same noises presented in complex scenarios might indicate the possibility of a more economical approach, at least to noises between which loudness differs greatly.