Both hearing loss and age degrade monaural fine-structure processing, with hearing loss dominant.

Evidence

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. — Dijk, Pim van, Physiology, Psychoacoustics and…, 791