Spectral and modulation indices for annoyance-relevant features of urban road single-vehicle pass-by noises.

The models that relate noise annoyance assessments to noise signal parameters are mainly based on energy-related indices (e.g., LDEN). However, various studies have shown that sound characteristics of environmental noises linked to temporal and spectral signal features also influence noise annoyance responses. In order to enhance noise annoyance models, an adequate perception-related characterization of these influential acoustical features is essential. On the basis of urban road single-vehicle pass-by noises, this study will show the identification of noise characteristics that rely on spectral and temporal signal properties and that are related to noise annoyance. Based on a semantic differential test with a verbalization task, it will be shown that the sensation dull/shrill, related to the spectral content of the noises and the modulation-related sensations sputtering and nasal are linked to annoyance. The sensation dull/shrill could be characterized using the index TETC (Total Energy of Tonal Components within critical bands from 16 to 24 barks). The correlation of sputtering and nasal sensations with psychoacoustic indices was unsatisfactory. Two alternative indices are proposed to improve the characterization of these specific sensations. It is shown that noise annoyance assessment benefits from taking the TETC index and the sputtering and nasal indices into account.