Echo threshold measurement based on headphone presentation

Abstract

Echo threshold(ET), as the upper threshold of the precedence effect, refers to the critical delay value when the listener transitions from perceiving a single fused sound image to two clear and separated sound images in the presence of two relatively delayed sounds. This study investigates the ET measurement using two kinds of headphone-based virtual sound source presentation methods, i.e., interaural time difference (ITD) lateralization and virtual auditory synthesis (VAS). The “lead-lag” paradigm was adopted in the experiment and an adaptive up-down procedure was used to measure ETs of four stimuli, including noise burst, speech, music and pink noise. The results demonstrate that ET is related to the type of signal and the presentation method. Long-duration signals (i.e., speech, music and pink noise) have greater ETs than short-duration signal(noise burst), which is due to the fact that the temporal overlap between lead and lag sound of long-duration signal would suppress the identification of the lag. ETs of ITD-based presentation were significantly greater than that of VAS-based method for long-duration signal, which indicate that different spatial cues produced by different presentation methods would influence the ET of long-duration signal.