Hearing loss primarily harms monaural TFS processing while age harms binaural TFS processing

Evidence

Thresholds for detecting IPDs in TFSp were positively correlated with absolute thresholds for both carrier frequencies (r = 0.45 for f c = 250 Hz; r = 0.40, for f c = 500 Hz). The correlations remained positive and significant when the effect of age was partialled out. Thus, hearing loss adversely affects the binaural processing of TFS. — Dijk, Pim van, Physiology, Psychoacoustics and…, 811

Abstract Within the cochlea, broadband sounds like speech and music are filtered into a series of narrowband signals, each of which can be considered as a relatively slowly varying envelope (ENV) imposed on a rapidly oscillating carrier (the temporal fine structure, TFS). Information about ENV and TFS is conveyed in the timing and short-term rate of nerve spikes in the auditory nerve. There is evidence that both hearing loss and increasing age adversely affect the ability to use TFS information, but in many studies the effects of hearing loss and age have been confounded. This paper summarises evidence from studies that allow some separation of the effects of hearing loss and age. The results suggest that the monaural processing of TFS information, which is important for the perception of pitch and for segregating speech from background sounds, is adversely affected by both hearing loss and increasing age, the former being more important. The monaural processing of ENV information is hardly affected by hearing loss or by increasing age. The binaural processing of TFS information, which is important for sound localisation and the binaural masking level difference, is also adversely affected by both hearing loss and increasing age, but here the latter seems more important. — Dijk, Pim van, Physiology, Psychoacoustics and…, 790

Categorization

• XREF: The King et al. 46-subject age-and-loss matrix data resonates with the reader’s interest in parsing age from loss confounds.
• corroborated: 2 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 811; Dijk, Pim van, Physiology, Psychoacoustics and…, 790