Perceptual evaluation of simulated auditory source width expansion

Abstract

In this work, we examine the effect of timbre of the signal on auditory source width (ASW). The timbre of the signal is varied as low pass, high pass and band pass filtered white Gaussian noise of different bandwidths. We also study the ASW perception of a time-varying multi-component music signal (violin). Three normal hearing listeners rate the perceptual ASW of these stimuli on a scale of (0–120)% using a MUSHRA-type presentation. The stimuli are presented on a linear loudspeaker array. Amongst noise stimuli, it is found that low pass stimuli of cut-off frequency of 250 Hz gives the widest ASW perception on an average. This stimuli creates monotonic ASW perception with respect to change in number of loud speakers (physical source width). For a multi-component music signal, we observe that widest ASW is produced with a random inter-channel delay, compared to synchronous stimuli and segmental jittered stimuli. Thus, through this work, we develop an experimental methodology to study the large auditory source width using a linear loudspeaker array in an anechoic setup.