Cochlear compression: Effects of low-frequency biasing on quadratic distortion product otoacoustic emission

Bian, Lin

doi:10.1121/1.1819501

Cited by 24 publications

(29 citation statements)

References 50 publications

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“…Further, the observed modulation pattern of the f2-f1 DPOAE is much stronger than the modulation pattern of 2f1-f2. This is comparable with the results of previous studies (Bian 2004;Kössl 1996, 1997;Lukashkin and Russell 2005), where either acoustical biasing with a lowfrequency tone or biasing by direct electrical stimulation of the hair cells was used. Further, the changes in DPOAE modulation patterns in dependence on the bias tone level (e.g., Fig.…”

Section: Low-frequency Biasing Of the Cochlear Partitionsupporting

confidence: 81%

“…This was shown in previous studies and in the present study using low-frequency biasing (Bian 2004;Kössl 1996, 1997;Lukashkin and Russell 2005). The pronounced changes in the f2-f1 level during CAS could therefore be interpreted as an efferent-induced shift of the OP of the cochlear amplifier transfer function.…”

Section: Low-frequency Biasing Of the Cochlear Partitionmentioning

confidence: 48%

“…In experiments applying acoustical and electrical biasing of the cochlear partition to induce periodical shifts of the operating point (OP) of the cochlear amplifier transfer function, it could be shown that the QDT f2-f1 is a very sensitive indicator for changes in the OP of the transfer function if the OP is situated near the point of inflection (Bian 2004; Kö ssl 1996, 1997;Lukashkin and Russell 2005). The generation of cochlear two-tone distortions depends on the transfer characteristic of auditory transduction and can be modeled by using a nonlinear transfer function, such as a second-order Boltzmann function (for further details see METHODS), similar to those that are used to describe mechanoelectrical transduction (e.g., Kros et al 1992).…”

Section: Introductionmentioning

confidence: 99%

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Contralateral Acoustic Stimulation Modulates Low-Frequency Biasing of DPOAE: Efferent Influence on Cochlear Amplifier Operating State?

Abel¹,

Wittekindt²,

Kössl³

2009

Journal of Neurophysiology

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Abel C, Wittekindt A, Kössl M. Contralateral acoustic stimulation modulates low-frequency biasing of DPOAE: efferent influence on cochlear amplifier operating state? J Neurophysiol 101: 2362-2371. First published March 11, 2009 doi:10.1152/jn.00026.2009. The mammalian efferent medial olivocochlear system modulates active amplification of low-level sounds in the cochlea. Changes of the cochlear amplifier can be monitored by distortion product otoacoustic emissions (DPOAEs). The quadratic distortion product f2-f1 is known to be sensitive to changes in the operating point of the amplifier transfer function. We investigated the effect of contralateral acoustic stimulation (CAS), known to elicit efferent activity, on DPOAEs in the gerbil. During CAS, a significant increase of the f2-f1 level occurred already at low contralateral noise levels (20 dB SPL), whereas 2f1-f2 was much less affected. The effect strength depended on the CAS level and as shown in experiments with pure tones on the frequency of the contralateral stimulus. In a second approach, we biased the position of the cochlear partition and thus the cochlear amplifier operating point periodically by a ipsilateral low-frequency tone, which resulted in a phase-related amplitude modulation of f2-f1. This modulation pattern was changed considerably during contralateral noise stimulation, in dependence on the noise level. The experimental results were in good agreement with a simple model of distortion product generation and suggest that the olivocochlear efferents might change the operating state of cochlear amplification. I N T R O D U C T I O NOuter hair cells (OHCs) are one of the key elements of nonlinear cochlear amplification, which is responsible for high inner ear sensitivity and exquisite frequency resolution (for review see Ashmore 2008;Dallos et al. 2006;Robles and Ruggero 2001). They are densely innervated by efferent fibers that originate in the brain stem and can modulate the electromotile response characteristics of OHC and cochlear mechanics (reviews: Guinan 1996; Russell and Lukashkin 2008). Details of the physiological mechanisms of the medial olivocochlear (MOC) efferent system, its influence on the cochlear mechanics, and its biological function are still under discussion. Activation of the olivocochlear bundle has a substantial, predominantly suppressive effect on basilar membrane motion (e.g., Cooper and Guinan 2003;Murugasu and Russell 1996;Russell and Murugasu 1997) and auditory nerve activity (e.g., Guinan and Gifford 1988a;Guinan et al. 2005;Wiederhold and Kiang 1970) in response to low-level tones. The influence of efferent activity on the cochlear amplification can be investigated by recording otoacoustic emissions (for review see Guinan 2006) that are generated as a by-product of amplification of low-level sound by outer hair cells (Kemp 2002;Probst et al. 1991).In the present study, distortion product otoacoustic emissions (DPOAEs), evoked by simultaneously stimulating the ear with two pure-tone stimuli (primary tones) of differen...

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Section: Low-frequency Biasing Of the Cochlear Partitionsupporting

confidence: 81%

Section: Low-frequency Biasing Of the Cochlear Partitionmentioning

confidence: 48%

Section: Introductionmentioning

confidence: 99%

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Contralateral Acoustic Stimulation Modulates Low-Frequency Biasing of DPOAE: Efferent Influence on Cochlear Amplifier Operating State?

Abel¹,

Wittekindt²,

Kössl³

2009

Journal of Neurophysiology

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“…We observed a similar, differential effect on QDPs and CDPs in the present work, but the oscillation is much slower, it is not coupled to the LF sound period and the oscillation occurs after the LF sound offset. QDPs and CDPs represent different properties of MET transfer functions and are believed to reflect compression and gain of cochlear transduction, respectively (Bian 2004). This can result in opposite magnitude changes of QDPs and CDPs when the OPs are sufficiently shifted by manipulations of the cochlea, including LF biasing (Frank and Kossl 1997;Drexl et al 2012), or by stimulation of the efferent system Althen et al 2012).…”

Section: Lf Sound-induced Changes Of Level and Phase Of Dpoaesmentioning

confidence: 99%

Multiple Indices of the ‘Bounce’ Phenomenon Obtained from the Same Human Ears

Drexl

Überfuhr

Weddell

et al. 2013

JARO

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Loud low-frequency sounds can induce temporary oscillatory changes in cochlear sensitivity, which have been termed the 'bounce' phenomenon. The origin of these sensitivity changes has been attributed to slow fluctuations in cochlear homeostasis, causing changes in the operating points of the outer hair cell mechanoelectrical and electro-mechanical transducers. Here, we acquired three objective and subjective measures resulting in a comprehensive dataset of the bounce phenomenon in each of 22 normal-hearing human subjects. We analysed the level and phase of cubic and quadratic distortion product otoacoustic emissions and the auditory thresholds before and after presentation of a low-frequency stimulus (30 Hz sine wave, 120 dB SPL, 90 s) as a function of time. In addition, the perceived loudness of temporary, tinnitus-like sensations occurring in all subjects after cessation of the low-frequency stimulus was tracked over time. The majority of the subjects (70 %) showed a significant, biphasic change of quadratic, but not cubic, distortion product otoacoustic emissions of about 3-4 dB. Eighty-six percent of the tested subjects showed significant alterations of hearing thresholds after low-frequency stimulation. Four different types of threshold changes were observed, namely monophasic desensitisations (the majority of cases), monophasic sensitisations, biphasic alterations with initial sensitisation and biphasic alterations with initial desensitisation. The similar duration of the three bounce phenomenon measures indicates a common origin. The current findings are consistent with the hypothesis that slow oscillations of homeostatic control mechanisms and associated operating point shifts within the cochlea are the source of the bounce phenomenon.

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“…Frank and Kössl 1996;Russell 1998, 1999;Drexl et al 2012) There is evidence that quadratic distortions provide information about a frequency specific modulation of the operating point of the cochlear amplification (Abel et al 2009;Wittekindt et al 2009;Althen et al 2012). In addition, dynamic compression of the transducer gain also can change the amplitude of the f2-f1 DPOAE (Bian 2004).…”

Section: Introductionmentioning

confidence: 99%

Influence of Ketamine–Xylazine Anaesthesia on Cubic and Quadratic High-Frequency Distortion-Product Otoacoustic Emissions

Schlenther

Voss

Kössl

2014

JARO

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Ketamine is a dissociative anaesthetic, analgesic drug as well as an N-methyl-D-aspartate receptor antagonist and has been reported to influence otoacoustic emission amplitudes. In the present study, we assess the effect of ketamine-xylazine on high-frequency distortion-product otoacoustic emissions (DPOAE) in the bat species Carollia perspicillata, which serves as model for sensitive high-frequency hearing. Cubic DPOAE provide information about the nonlinear gain of the cochlear amplifier, whereas quadratic DPOAE are used to assess the symmetry of cochlear amplification and potential efferent influence on the operating state of the cochlear amplifier. During anaesthesia, maximum cubic DPOAE levels can increase by up to 35 dB within a medium stimulus level range from 35 to 60 dB SPL. Close to the -10 dB SPL threshold, at stimulus levels below about 20-30 dB SPL, anaesthesia reduces cubic DPOAE amplitudes and raises cubic DPOAE thresholds. This makes DPOAE growth functions steeper. Additionally, ketamine increases the optimum stimulus frequency ratio which is indicative of a reduction of cochlear tuning sharpness. The effect of ketamine on cubic DPOAE thresholds becomes stronger at higher stimulus frequencies and is highly significant for f2 frequencies above 40 kHz. Quadratic DPOAE levels are increased by up to 25 dB by ketamine at medium stimulus levels. In contrast to cubic DPOAEs, quadratic DPOAE threshold changes are variable and there is no significant loss of sensitivity during anaesthesia. We discuss that ketamine effects could be caused by modulation of middle ear function or a release from ipsilateral efferent modulation that mainly affects the gain of cochlear amplification.

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Cochlear compression: Effects of low-frequency biasing on quadratic distortion product otoacoustic emission

Cited by 24 publications

References 50 publications

Contralateral Acoustic Stimulation Modulates Low-Frequency Biasing of DPOAE: Efferent Influence on Cochlear Amplifier Operating State?

Contralateral Acoustic Stimulation Modulates Low-Frequency Biasing of DPOAE: Efferent Influence on Cochlear Amplifier Operating State?

Multiple Indices of the ‘Bounce’ Phenomenon Obtained from the Same Human Ears

Influence of Ketamine–Xylazine Anaesthesia on Cubic and Quadratic High-Frequency Distortion-Product Otoacoustic Emissions

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