Abstract
When two pure tones (or primaries) of slightly different frequencies (f 1 and f 2; f 2 > f 1) are presented to the ear, new frequency components not present in the stimulus may be recorded in the ear canal. These new components are termed distortion product otoacoustic emissions (DPOAEs) and are generated by nonlinear interaction of the primaries within the cochlea. It has been conjectured that the level of the 2f 1 − f 2 DPOAE component is maximal when the primaries produce approximately equal excitation at the f 2 cochlear region because this is where and when the overlap between the traveling waves evoked by the two primaries is maximal. This region, however, almost certainly shifts as the level of the primaries increases following the well-known level-dependent shift of the cochlear traveling-wave peak. Furthermore, mutual suppression between the primaries may also affect the combination of primary levels that maximizes the DPOAE levels. This report summarizes our attempts to test these conjectures using psychophysical masking methods that are commonly applied to infer human cochlear responses. Test frequencies of 0.5, 1 and 4 kHz and a fixed frequency ratio of f 2/f 1 = 1.2 were considered. Results supported that maximal-level DPOAEs occur when the primaries produce comparable excitation at the cochlear site with CF ∼ f 2. They also suggest that the site of maximum interaction hardly shifts with increasing primary level and that mutual suppression between the primaries does not affect significantly the optimal DPOAE primary level rule.
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References
Carney LH, McDuffy MJ, Shekhter I (1999) Frequency glides in the impulse response of auditory-nerve fibers. J Acoust Soc Am 105:2384–2391
Johannesen PT, Lopez-Poveda EA (2008) Cochlear nonlinearity in normal-hearing subjects as inferred psychophysically and from distortion-product otoacoustic emissions. J Acoust Soc Am 124:2149–2163
Johnson TA, Neely ST, Garner CA, Gorga MP (2006) Influence of primary-level and primary-frequency ratios on human distortion product otoacoustic emissions. J Acoust Soc Am 119:418–428
Kummer P, Janssen T, Arnold W (1998) The level and growth behavior of the 2 f1-f2 distortion product otoacoustic emission and its relationship to auditory sensitivity in normal hearing and cochlear hearing loss. J Acoust Soc Am 103:3431–3444
Kummer P, Janssen T, Hulin P, Arnold W (2000) Optimal L(1)-L(2) primary tone level separation remains independent of test frequency in humans. Hear Res 146:47–56
Levitt H (1971) Transformed up-down methods in psychoacoustics. J Acoust Soc Am 49:467–477
Lopez-Poveda EA, Alves-Pinto A (2008) A variant temporal-masking-curve method for inferring peripheral auditory compression. J Acoust Soc Am 123:1544–1554
Lopez-Poveda EA, Johannesen PT (2009) Otoacoustic emission theories and behavioral estimates of human basilar membrane motion are mutually consistent. J Assoc Res Otolaryngol 10:511–523
Lopez-Poveda EA, Plack CJ, Meddis R (2003) Cochlear nonlinearity between 500 and 8000 Hz in listeners with normal hearing. J Acoust Soc Am 113:951–960
Neely ST, Johnson TA, Gorga MP (2005) Distortion-product otoacoustic emission measured with continuously varying stimulus level. J Acoust Soc Am 117:1248–1259
Nelson DA, Schroder AC, Wojtczak M (2001) A new procedure for measuring peripheral compression in normal-hearing and hearing-impaired listeners. J Acoust Soc Am 110:2045–2064
Oxenham AJ, Plack CJ (1997) A behavioral measure of basilar-membrane nonlinearity in listeners with normal and impaired hearing. J Acoust Soc Am 101:3666–3675
Robles L, Ruggero MA (2001) Mechanics of the mammalian cochlea. Physiol Rev 81:1305–1352
Rosengard PS, Oxenham AJ, Braida LD (2005) Comparing different estimates of cochlear compression in listeners with normal and impaired hearing. J Acoust Soc Am 117:3208–3241
Shaffer LA, Withnell RH, Dhar S, Lilly DJ, Goodman SS, Harmon KM (2003) Sources and mechanisms of DPOAE generation: Implications for the prediction of auditory sensitivity. Ear Hear 24:367–379
Shera CA, Guinan JJ Jr (2007) Cochlear traveling-wave amplification, suppression, and beamforming probed using noninvasive calibration of intracochlear distortion sources. J Acoust Soc Am 121:1003–1016
Wojtczak M, Oxenham AJ (2009) Pitfalls in behavioral estimates of basilar-membrane compression in humans. J Acoust Soc Am 125:270–281
Acknowledgments
Work supported by The Oticon Foundation, the Spanish Ministry of Science and Technology (BFU2006-07536), and Junta de Castilla y León (GR221).
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Lopez-Poveda, E.A., Johannesen, P.T. (2010). Otoacoustic Emissions Theories Can Be Tested with Behavioral Methods. In: Lopez-Poveda, E., Palmer, A., Meddis, R. (eds) The Neurophysiological Bases of Auditory Perception. Springer, New York, NY. https://doi.org/10.1007/978-1-4419-5686-6_1
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DOI: https://doi.org/10.1007/978-1-4419-5686-6_1
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