Interaural phase disparities lower masked thresholds by up to 25 dB for overlapping targets

Evidence

In complex acoustical environments, the auditory system makes use of various cues to group sound components from one particular sound source. These cues, sometimes referred to as object binding cues, are often associated with characteristics of the sound such as coherent level fluctuations in different frequency regions (as, e.g., observed in speech), or the location of the sources in space. Differences in location result, among others, in interaural differences. Psychoacousticians developed experiments to study how the human auditory system makes use of the information. For example, the ability to use interaural disparities is shown in experiments on binaural masking level differences (BMLD). The BMLD is a well investigated phenomenon that signifies the reduction in masked thresholds when a tonal signal and masker have disparate interaural cues. For a diotic narrowband masker, a tonal target can be detected at a 25 dB lower level when the interaural target phase is changed from 0 to ∏ (e.g. van de Par and Kohlrausch 1999 ). — Dijk, Pim van, Physiology, Psychoacoustics and…, 3465

Categorization

• DEFINE: Defines binaural masking level difference (BMLD) and its sharply quantified effect: 25 dB threshold reduction from a pi interaural phase shift.