Nd phase. The mean phase slopes, for instance, are nearly identical. Computing the bestfitting straight lines on the interval CF 6 0.5 kHz with CF 7.2 kHz ( ) yields near-CF phase-gradient delays of sSFOAE ffi 1:2560:3 ms and sBME ffi 1:2860:08 ms (BME: BM echo), exactly where the uncertainties represent the 95 self-assurance intervals estimated by bootstrap resampling.8 The similarities in between the SFOAE and BM echo spectra are consistent with model predictions of a widespread origin.F. Wave propagation delaysMeasurements of basilar-membrane motion and stimulusfrequency OAEs made inside the identical ears demonstrate that the prominent spectral Vorapaxar web ripples observed in BM mechanical transfer functions at low stimulus intensities (e.g., Rhode, 2007) constitute a mechanical MedChemExpress Pachymic acid interference pattern analogous towards the acoustic interference pattern created in ear-canal pressure by the emission of SFOAEs. When supplemented with mechanical irregularities to scatter forward-traveling waves, active cochlear models reproduce the big options of BM spectral ripples, which includes their gradual disappearance at higher intensities and their tight correlation with SFOAEs. We conclude that BM spectral ripples arise from multiple internal reflection of waves scattered within the cochlea. Analysis from the model shows that the magnitude of your BM ripples depends on the product RRstapes [see Eq. (three)], where R is the cochlear reflectance and Rstapes will be the stapes reflection coefficient for retrograde waves. According to coherent-reflection theory, R depends both on the distribution of micromechanical irregularities that scatter the wave and around the round-trip gain on the cochlear amplifier. Despite the fact that all of these quantities can be specified inside a cochlear model, none are yet known with any precision experimentally, and all presumably vary from animal to animal.A. BM ripples and standing wavesThe SFOAE and BM echo phase-gradient delays computed above give estimates of roundtrip propagation delays. For SFOAEs, the round-trip delay is from the earcanal to the area of scattering and back once again. For BM echoes, the round-trip delay contains propagation in the measurement point for the region of scattering, PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19918519 reverse travel for the stapes, and after that forward travel back for the measurement location. (The measurement location and also the region of reflection coincide when both are situated near the peak with the traveling wave.) These two delays, both about 1.25 ms for the present information, is often compared with all the delay associ2232 J. Acoust. Soc. Am., Vol. 133, No. four, AprilAccording to the model, BM ripples differ considerably from traditional standing-wave interference patterns, that are formed by the superposition of waves traveling in opposite directions (e.g., along a string or inside an organ pipe). By contrast, the interference giving rise to BM ripples occurs mainly involving two waves traveling within the very same (forward) path. As illustrated heuristically in Fig. 2 and derived in the model in Eq. (three), the two principal waves contributing towards the BM interference pattern are (1) the initial forward wave as a result of the stimulus and (2) the secondary forward wave arising from reflection on the reverse wave at theC. A. Shera and N. P. Cooper: Wave interference in the cochleastapes. (For simplicity, we are ignoring feasible higher-order reflections, which frequently create waves of smaller amplitude.) Even though a reverse-traveling wave is present within the model, its initial amplitude is generally tiny inside the reg.Nd phase. The mean phase slopes, for instance, are nearly identical. Computing the bestfitting straight lines around the interval CF 6 0.5 kHz with CF 7.2 kHz ( ) yields near-CF phase-gradient delays of sSFOAE ffi 1:2560:3 ms and sBME ffi 1:2860:08 ms (BME: BM echo), where the uncertainties represent the 95 self-assurance intervals estimated by bootstrap resampling.8 The similarities among the SFOAE and BM echo spectra are constant with model predictions of a typical origin.F. Wave propagation delaysMeasurements of basilar-membrane motion and stimulusfrequency OAEs made inside the very same ears demonstrate that the prominent spectral ripples observed in BM mechanical transfer functions at low stimulus intensities (e.g., Rhode, 2007) constitute a mechanical interference pattern analogous for the acoustic interference pattern designed in ear-canal stress by the emission of SFOAEs. When supplemented with mechanical irregularities to scatter forward-traveling waves, active cochlear models reproduce the important characteristics of BM spectral ripples, such as their gradual disappearance at greater intensities and their tight correlation with SFOAEs. We conclude that BM spectral ripples arise from multiple internal reflection of waves scattered within the cochlea. Analysis with the model shows that the magnitude with the BM ripples will depend on the item RRstapes [see Eq. (3)], where R will be the cochlear reflectance and Rstapes is definitely the stapes reflection coefficient for retrograde waves. In line with coherent-reflection theory, R depends each on the distribution of micromechanical irregularities that scatter the wave and around the round-trip achieve of your cochlear amplifier. Although all of those quantities is usually specified inside a cochlear model, none are however identified with any precision experimentally, and all presumably vary from animal to animal.A. BM ripples and standing wavesThe SFOAE and BM echo phase-gradient delays computed above offer estimates of roundtrip propagation delays. For SFOAEs, the round-trip delay is in the earcanal towards the area of scattering and back once more. For BM echoes, the round-trip delay contains propagation from the measurement point towards the area of scattering, PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19918519 reverse travel for the stapes, and then forward travel back for the measurement location. (The measurement place and also the region of reflection coincide when both are located close to the peak of your traveling wave.) These two delays, both about 1.25 ms for the present data, may be compared with all the delay associ2232 J. Acoust. Soc. Am., Vol. 133, No. four, AprilAccording to the model, BM ripples differ significantly from traditional standing-wave interference patterns, which are formed by the superposition of waves traveling in opposite directions (e.g., along a string or within an organ pipe). By contrast, the interference providing rise to BM ripples occurs mostly between two waves traveling in the same (forward) direction. As illustrated heuristically in Fig. two and derived in the model in Eq. (three), the two principal waves contributing towards the BM interference pattern are (1) the initial forward wave resulting from the stimulus and (two) the secondary forward wave arising from reflection of the reverse wave at theC. A. Shera and N. P. Cooper: Wave interference in the cochleastapes. (For simplicity, we are ignoring probable higher-order reflections, which typically make waves of smaller sized amplitude.) Even though a reverse-traveling wave is present inside the model, its initial amplitude is typically tiny inside the reg.