Cochlear Mechanics, Otoacoustic Emissions, and Medial Olivocochlear Efferents: Twenty Years of Advances and Controversies Along with Areas Ripe for New Work
Reviewed are progress, exciting new developments, and areas that need work. Topics considered are: Cochlear amplification is from energy injected into the traveling wave by outer-hair-cell somatic motility. Calcium-activated stereocilia motility does not work at high frequencies because of the slowness of calcium binding and unbinding. Cochlear mechanics and micromechanics in the apical half of the cochlea are different from in the base. Cochlear micromechanics and the multiple fluid drives to inner hair cell (IHC) stereocilia. Interaction of the multiple IHC fluid drives can explain phase reversals in auditory nerve fiber responses without phase reversals in basilar membrane responses. The mechanisms by which medial olivocochlear (MOC) efferents change cochlear mechanics and micromechanics. The generation mechanisms for otoacoustic emissions (OAEs). Distortion product OAEs (DPOAEs) travel backward by slow traveling waves. Stimulus frequency OAEs (SFOAEs) arise mainly from near the peak of the traveling wave. Using OAEs to reveal cochlear properties. Cochlear tuning is sharper in humans than in cats, guinea pigs, and chinchillas. Measuring MOC effects using changes in OAEs and the need for high OAE signal-to-noise ratios. MOC effects in humans. The role of MOC efferents in hearing. MOC activity makes it easier to hear signals in noise. MOC activity and selective attention. MOC activity reduces acoustic trauma.
This work was supported by NIH NIDCD RO1 000235 and RO1 005977.
- Backus, B. C., & Guinan, J. J., Jr. (2007). Measurement of the distribution of medial olivocochlear acoustic reflex strengths across normal-hearing individuals via otoacoustic emissions. Journal of the Association for Research in Otolaryngology, 8(4), 484–496.PubMedCentralPubMedCrossRefGoogle Scholar
- Cooper, N. P., & Guinan, J. J., Jr. (2011). Efferent insights into cochlear mechanics. In C. A. Shera & E. S. Olson (Eds.), What fire is in mine ears: Progress in auditory biomechanics (Vol. 1403, pp. 396–402). Melville, NY: American Institute of Physics.Google Scholar
- Guinan, J. J., Jr. (1990). Changes in stimulus frequency otoacoustic emissions produced by two-tone suppression and efferent stimulation in cats. In P. Dallos, C. D. Geisler, J. W. Matthews & C. R. Steele (Eds.), Mechanics and biophysics of hearing (pp. 170–177). New York: Springer-Verlag.CrossRefGoogle Scholar
- Guinan, J. J., Jr. (1996). The physiology of olivocochlear efferents. In P. J. Dallos, A. N. Popper & R. R. Fay (Eds.), The cochlea (pp. 435–502). New York: Springer-Verlag.Google Scholar
- Joris, P. X., Bergevin, C., Kalluri, R., Mc Laughlin, M., Michelet, P., van der Heijden, M., & Shera, C. A. (2011). Frequency selectivity in Old-World monkeys corroborates sharp cochlear tuning in humans. Proceedings of the National Academy of Sciences of the USA, 108(42), 17516–17520.PubMedCentralPubMedCrossRefGoogle Scholar
- Lichtenhan, J. T. (2011). Effects of low-frequency biasing on otoacoustic and neural measures suggest that stimulus-frequency otoacoustic emissions originate near the peak region of the traveling wave. Journal of the Association for Research in Otolaryngology, 13, 17–28.PubMedCentralPubMedCrossRefGoogle Scholar
- Nowotny, M., & Gummer, A. W. (2006). Nanomechanics of the subtectorial space caused by electromechanics of cochlear outer hair cells. Proceedings of the National Academy of Sciences of the USA, 103(7), 2120–2125.7–Google Scholar
- Ruggero, M. A., Rich, N. C., Shivapuja, B. G., & Temchin, A. N. (1996). Auditory-nerve responses to low-frequency tones: Intensity dependence. Auditory Neuroscience, 2, 159–185.Google Scholar
- Shera, C. A., Tubis, A., Talmadge, C. L., & Guinan, J. J., Jr. (2004). The dual effect of “suppressor” tones on stimulus-frequency otoacoustic emissions. Association for Research in Otolaryngology Abstracts, 27, Abs. 776.Google Scholar
- Siegel, J. H., Temchin, A. N., & Ruggero, M. (2003). Empirical estimates of the spatial origin of stimulus-frequency otoacoustic emissions. Association for Research in Otolaryngology Abstracts, 26, Abstract 679.Google Scholar
- Siegel, J. H., Cerka, A. J., Recio-Spinoso, A., Temchin, A. N., van Dijk, P., & Ruggero, M. (2005). Delays of stimulus-frequency otoacoustic emissions and cochlear vibrations contradict the theory of coherent reflection filtering. Journal of the Acoustical Society of America, 118(4), 2434–2443.PubMedCrossRefGoogle Scholar