SOAE bouncing is not caused by middle-ear impedance changes

Evidence

After LF sound stimulation, 56 of these 80 SOAEs increased in both sound level and frequency. This increase was followed by a decrease of both level and frequency relative to pre-exposure (see Fig. 2a ). — Dijk, Pim van, Physiology, Psychoacoustics and…, 3703 (#expands, via linked claim)

The second function of the middle ear is to provide some protection for the hearing system from the effects of loud sounds, whether from external sources or the individual concerned. This occurs as a result of the action of two muscles in the middle ear: the tensor tympani and the stapedius muscle. These muscles contract automatically in response to sounds with levels greater than approximately 75 dB(SPL), and they have the effect of increasing the impedance of the middle ear by stiffening the ossicular chain. This reduces the efficiency with which vibrations are transmitted from the tympanic membrane to the inner ear and thus protects the inner ear to some extent from loud sounds. Approximately 12 to 14 dB of attenuation is provided by this protection mechanism, but this is for frequencies below 1 kHz only. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 541 (#contradicts, via linked claim)

Categorization

• corroborated: 2 independent passages support this claim
• XREF: connects to: Low-frequency Bounce occurs even with the ear canal left open; The SOAE Bounce reflects a calcium-driven homeostatic readjustment in outer hair cells. — Dijk, Pim van, Physiology, Psychoacoustics and…, 3703; Otosclerosis stiffens ossicle movement and attenuates transmitted sound (+6 more)

Related

• The middle ear amplifies sound pressure through three mechanical mechanisms (similarity 0.89)
• Otosclerosis stiffens ossicle movement and attenuates transmitted sound (similarity 0.88)
• The middle ear both transmits sound and protects against loud noise (similarity 0.86)
• Low-frequency Bounce occurs even with the ear canal left open (similarity 0.85)
• An acoustic reflex desensitizes the ear to protect cochlear hair cells (similarity 0.84)
• Low-frequency sound’s after-effects arise from calcium homeostasis in outer hair cells (similarity 0.84)
• Middle-ear muscles automatically stiffen to block loud sounds (similarity 0.84)
• Outer and middle ear transfer function determines loudness across frequency. (similarity 0.84)
• SOAE bouncing is not caused by the probe blocking the ear canal (similarity 0.83)
• Low-frequency sound exposure triggers long-lasting damped oscillations in spontaneous otoacoustic emissions. (similarity 0.83)
• Low-frequency exposure measurably alters cochlear amplifier gain via outer hair cell activity (similarity 0.83)
• The SOAE Bounce reflects a calcium-driven homeostatic readjustment in outer hair cells. (similarity 0.83)
• Low-frequency exposure temporarily activates new otoacoustic emissions that were previously absent in most ears. (similarity 0.83)
• Low-frequency sound can awaken silent inner ears to emit spontaneous tones (similarity 0.82)
• SOAE Bouncing occurs in open-ear listening to real-world low-frequency sound sources. (similarity 0.82)

Broader Connections

• Low-frequency sound exposure triggers long-lasting damped oscillations in spontaneous otoacoustic emissions. #expands (0.80) — Dijk, Pim van, Physiology, Psychoacoustics and…, 3703
• Middle-ear muscles automatically stiffen to block loud sounds #contradicts (0.75) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 541
• Otosclerosis stiffens ossicle movement and attenuates transmitted sound #complicates (0.72)
• Outer and middle ear transfer function determines loudness across frequency. #complicates (0.72)
• Outer and middle ear structures provide frequency-specific amplification of incoming sound #complicates (0.72) — Jennifer Lentz, Psychoacoustics- Perception of Normal…, 212
• The middle ear amplifies sound pressure through three mechanical mechanisms #complicates (0.70)
• Impedance mismatch determines whether a sound pulse reflects or passes #complicates (0.70)