Perceptual insensitivity to low-frequency sound masks its physiological impact on the inner ear

Evidence

For decades, low-frequency sound, i.e. sound with frequencies lower than 250 Hz (Berglund et al. 1996 ), has been considered to largely bypass the inner ear even at intense levels, simply because human hearing thresholds for frequencies below 250 Hz are relatively high. Recent evidence from animal models shows that physiological cochlear responses to LF sound are even larger than those evoked by equal-level, higher frequencies in the more sensitive range of hearing (Salt et al. 2013 ). No data for human subjects are available, but, considering the higher sensitivity of humans for LF sounds, similar results can be expected (Salt et al. 2013 ). … Perceptual thresholds essentially reflect the sensitivity of inner hair cells (IHCs), which are functionally coupled to inner ear fluids (Nowotny and Gummer 2006 ; Guinan 2012 ). IHCs are therefore sensitive to basilar-membrane velocity, which decreases with decreasing frequency. OHCs, in contrast, are mechanically linked to both the basilar membrane and the tectorial membrane. OHCs are therefore sensitive to basilar membrane displacement (Dallos et al. 1982 ; Dallos 1986 ), which does not decrease with decreasing stimulus frequency. Thus, OHCs are more sensitive to LF sound than IHCs and it is this difference in LF sensitivity, which contributes to the LF limit of sound perception (Salt and Hullar 2010 ; Salt et al. 2013 ). — Dijk, Pim van, Physiology, Psychoacoustics and…, 3704 (#qualifies, via linked claim)

Categorization

• XREF: connects to: Internal physiological noise from blood flow and heartbeat raises low-frequency thresholds — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 1148; Physical frequency is the wrong scale for describing inner-ear effects; Inner-ear damage permanently corrupts higher-level auditory perception, not just thresholds — Toole, Floyd E, Sound reproduction- the acoustics and…, 1879 (+5 more)

Related

• Low-frequency sound triggers larger cochlear responses than comparable higher frequencies. (similarity 0.95)
• Physical frequency is the wrong scale for describing inner-ear effects (similarity 0.94)
• Outer hair cells respond better than inner hair cells to low-frequency sound (similarity 0.89)
• Intense low-frequency sound alters inner ear function even though we barely hear it (similarity 0.88)
• Internal physiological noise from blood flow and heartbeat raises low-frequency thresholds (similarity 0.84)
• Low-frequency exposure measurably alters cochlear amplifier gain via outer hair cell activity (similarity 0.84)
• Active outer hair cell processing boosts internal response levels by up to 40 dB (similarity 0.84)
• Inner-ear damage permanently corrupts higher-level auditory perception, not just thresholds (similarity 0.83)
• Outer hair cells encode displacement and therefore stay responsive at low frequencies. (similarity 0.82)
• Outer hair cell loss reduces hearing sensitivity by up to 60 dB (similarity 0.82)
• Human hearing sensitivity peaks near 4 kHz and falls off at both extremes (similarity 0.82)
• Low-frequency sound can awaken silent inner ears to emit spontaneous tones (similarity 0.81)
• Hearing loss impairs frequency selectivity beyond what stimulus level differences explain. (similarity 0.81)
• Loud music damages cochlear structures in distinct ways producing distinct perceptual deficits (similarity 0.81)
• Noise-induced hearing loss begins with impairment of outer hair cells (similarity 0.81)

Broader Connections

• Low-frequency sound triggers larger cochlear responses than comparable higher frequencies. #qualifies (0.80) — Dijk, Pim van, Physiology, Psychoacoustics and…, 3704
• Wider peripheral tuning from hearing loss suppresses low-frequency fluctuation amplitude #responds-to (0.75)