On the acoustical quality of conversational speech inside vehicles

Paper in proceeding, 2010

The influence of room acoustics and driving noise in vehicle interiors on the subjectively perceived sound quality of conversations between passengers was studied. A laboratory test with 25 participants was performed to assess the impact of interior transfer functions and driving noise at different velocities. The interference of other factors like varying speech spectra and temporal fluctuations of the driving noise was minimized as far as possible. A very strong relationship of speech-to-noise ratio and the subjective speech quality was found. Consequentially, the speech signal level, due to the influence of different interior room acoustics, seems to play a more important role than the varied speech timbre or other parameters. Further interrelations of acoustical and psychoacoustical metrics and parameters were investigated as well.