Listeners can discriminate interaural time differences of just tens of microseconds below 1.3 kHz.

Evidence

Sensitivity to interaural time differences (ITDs) in particular has received much attention, due in part to the exquisite temporal performance observed; for sound frequencies lower than about 1.3 kHz, ITDs of just a few tens of microseconds are discriminable, observed both at the neural and behavioural levels. Sensitivity to ITDs decreases with ageing (Herman et al. 1977 ; Abel et al. 2000 ; Babkoff et al. 2002 ), and is typically impaired in hearing loss, albeit variability across individuals and aetiologies (see Moore et al. 1991 , for review), with reduced sensitivity most apparent when trying to localise sources in background noise (Lorenzi et al. 1999 ). ITD processing may also remain impaired following surgery to correct conductive hearing loss (Wilmington et al. 1994 ), and sensitivity to ITDs is typically poor in users of hearing technologies such as bilateral cochlear implants (CIs). — Dijk, Pim van, Physiology, Psychoacoustics and…, 2951

Categorization

• QUESTION: The 1.3 kHz upper limit and the ‘few tens of microseconds’ threshold — what mechanistic reason explains the 1.3 kHz cutoff specifically? Worth chasing the physiological basis.