High- and low-side suppression rest on different cochlear mechanisms

Evidence

Previous studies have examined the relationship between ANF 2TS and chronic low-level noise exposure coupled with ageing in the Mongolian gerbil (Schmiedt et al. 1990 ; Schmiedt and Schultz 1992 ), and following an acute intense noise exposure in the cat (Miller et al. 1997 ). Ageing in a noisy environment was associated with a loss of 2TS. Schmiedt and colleagues often found complete absence of high-side 2TS, with sparing of low-side 2TS, even in cochlear regions with up to 60 % outer-hair-cell loss; suggesting potentially different mechanisms for lowand high-side suppression. — Dijk, Pim van, Physiology, Psychoacoustics and…, 3876

Categorization

• XREF: Connects to the reader’s broader reading on how the cochlea’s nonlinear compressive amplifier (outer hair cells) is disrupted in hearing loss; both 2TS and DPOAE results in this chapter corroborate that story. — connects to: Two-tone suppression lets strong signal components override weaker nearby ones; Comparing linear off-frequency and compressive on-frequency maskers estimates cochlear gain; Two-tone suppression is an instantaneous reduction of basilar membrane response
• QUESTION: What structural mechanism could keep low-side suppression intact while high-side suppression is lost under the same 60% outer-hair-cell loss?
• corroborated: 3 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 3876