Effects of the modulated delay-time interval of the single reflection on subjective preference

Abstract

In the past, experimental results of the sound-pressure level (SPL) were obtained which showed that the indoor sound field is regarded as a time-variant system due to an air current. Using the time-variant model represented by the direct sound and the varying delay time of single reflection, an experiment was performed on an effect on subjective preference. This experiment was focused on the effect of the modulation interval (Δ) of the delay time of the single reflection. The delay time of reflection (Δt1) was adjusted to the most preferred delay time of reflection which was obtained by the experiments for the time-invariant sound field. In the case of fast tempo music, where the minimum value of the effective duration of the autocorrelation function is τemin=43 ms, the scale value of subjective preference is higher in a time-variant sound field than a time-invariant one. On the other hand, in the case of slow tempo music, τemin=127 ms, such an effect could not be found. It is suggested that a time-variant sound field might have a positive effect on subjective preference in the performance of a fast tempo music.