Otoacoustic and psychophysical estimates of efferent gain disagree due to stimulus constraints

Evidence

Masker levels at threshold obtained using a 4-kHz masker range from about 25 to 45 dB SPL, with the greatest masker level at threshold (about 45 dB SPL) associated with the presence of a precursor with a frequency close to that of the signal. Comparing masker levels at threshold for onand off-frequency maskers in the presence of a precursor (elicits efferent activation) with masker levels obtained in the absence of precursor (absence of efferent activation), it can be seen that the greatest change in masker level at threshold (of about 20 dB) occurs when there is an on-frequency masker, rather than an off-frequency masker, and this change is greatest when the precursor frequency is the same as, or just below, the 4-kHz signal. — Dijk, Pim van, Physiology, Psychoacoustics and…, 5972 (#qualifies, via linked claim)

Categorization

• XREF: connects to: Brain efferents can dynamically adjust cochlear gain during listening; Otoacoustic emission levels predict individual decision weights in level discrimination tasks — Dijk, Pim van, Physiology, Psychoacoustics and…, 5795; Human efferent tuning measured psychoacoustically matches otoacoustic-emission measures (+3 more)

Related

• The modeled efferent effects likely generalize to natural acoustic hearing (similarity 0.92)
• Efferent cochlear gain reduction is greatest when the precursor matches the signal frequency (similarity 0.92)
• Human efferent tuning measured psychoacoustically matches otoacoustic-emission measures (similarity 0.87)
• Efferent cochlear gain reduction is frequency-selective around the signal frequency. (similarity 0.87)
• Inferred basilar-membrane gain in humans is about 41 dB at 4 kHz (similarity 0.86)
• Medial olivocochlear efferent feedback reduces cochlear gain most for frequencies near the signal (similarity 0.85)
• Efferent effect is frequency-tuned, strongest nearest the test frequency (similarity 0.85)
• Cochlear gain reduction via efferents is sharply tuned with a 1300 Hz bandwidth. (similarity 0.84)
• The efferent effect is frequency-tuned along the cochlear tonotopic axis in humans (similarity 0.84)
• Efferent gain effects were mapped by precursors swept across nine centre frequencies (similarity 0.84)
• Efferent inhibition is strongest for tones near the cochlear site’s frequency (similarity 0.84)
• Masking measured within the efferent onset delay isolates gain reduction cleanly (similarity 0.84)
• Efferent gain reduction is strongest for tones near the target characteristic frequency. (similarity 0.84)
• Signal durations under the efferent onset delay isolate the efferent effect on cochlear gain (similarity 0.84)
• Psychoacoustic measures probe efferent function even where OAEs fail (similarity 0.84)

Broader Connections

• Efferent cochlear gain reduction is greatest when the precursor matches the signal frequency #qualifies (0.72) — Dijk, Pim van, Physiology, Psychoacoustics and…, 5972