Influence of recording/playback technique on noise annoyance ratings

In previous studies of perception and response to sounds, several methods have been adopted both with regard to recording techniques (monophonic or binaural recordings), playback techniques (through headphones or loudspeakers) and subjective evaluation techniques. In regard to recording and playback techniques very little is known on how these techniques affect the perception and overall response. This project investigates if there is a difference in perception and response related to annoyance, loudness and unpleasantness between monophonic recordings played back through a loudspeaker (standard technique in annoyance experiments), and binaural recordings played back via headphones (a more recent technique giving a more realistic experience especially for spatial properties of the sound). A major difference between the two recording and playback techniques is their ability - or lack of ability - to reproduce spatial properties of the sound. A further difference exists for low frequencies, which at higher sound pressure levels do not only affect the hearing but also give sensations in other parts of the body, mainly the chest and abdomen. An ear exposure (headphones) may therefore give another sensation than a full body exposure (loudspeaker). The project also investigates various psychometric methods for achieving responses from subjects. Many of the response methods used today are based on short-term comparisons of sounds that cannot directly be used to rate annoyance. One important factor in this project is to assess the possibility to adapt short-term evaluations to estimate long-term annoyance. Supported by STVF/FTP.