Effect of contralateral pure tone stimulation on distortion emissions suggests a frequency-specific functioning of the efferent cochlear control.

نویسندگان

  • H Althen
  • A Wittekindt
  • B Gaese
  • M Kössl
  • C Abel
چکیده

Contralateral acoustic stimulation (CAS) with white noise and pure tone stimuli was used to assess frequency specificity of efferent olivocochlear control of cochlear mechanics in the gerbil. Changes of the cochlear amplifier can be monitored by distortion product otoacoustic emissions (DPOAEs), which are a byproduct of the nonlinear amplification by the outer hair cells. We used the quadratic DPOAE f2-f1 as ipsilateral probe, as it is known to be sensitive to efferent olivocochlear activity. White noise CAS, used to evoke efferent activity, had maximal effects on the DPOAE level for f2-stimulus frequencies of 5-7 kHz. The dominant effect during CAS was a DPOAE level increase of up to 13.5 dB. The frequency specificity of the olivocochlear system was evaluated by presenting pure tones (0.5-38 kHz) as contralateral stimuli to evoke efferent activity. Maximal DPOAE level changes were triggered by CAS frequencies close to the frequency of the DPOAE elicitor tones (tested f2 range: 2.5-15 kHz). The effective CAS frequency range covered 1.4-2.4 octaves and was centered 0.42 octaves below the DPOAE elicitor tone f2. The frequency-specific effect of CAS with pure tones suggests a dedicated central control of mechanical adjustments for peripheral frequency processing.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

TITEL 1 Contralateral acoustic stimulation modulates low - frequency biasing of DPOAE – efferent

1 The mammalian efferent medial olivo-cochlear system modulates active amplification of low2 level sounds in the cochlea. Changes of the cochlear amplifier can be monitored by distortion 3 product otoacoustic emissions (DPOAEs). The quadratic distortion product f2-f1 is known to 4 be sensitive to changes in the operating point of the amplifier transfer function. We 5 investigated the effect of ...

متن کامل

Contralateral acoustic stimulation modulates low-frequency biasing of DPOAE: efferent influence on cochlear amplifier operating state?

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 contralate...

متن کامل

Evaluation of the olivocochlear efferent reflex strength in the susceptibility to temporary hearing deterioration after music exposure in young adults.

The objective of the current study was to evaluate the predictive role of the olivocochlear efferent reflex strength in temporary hearing deterioration in young adults exposed to music. This was based on the fact that a noise-protective role of the medial olivocochlear (MOC) system was observed in animals and that efferent suppression (ES) measured using contralateral acoustic stimulation (CAS)...

متن کامل

Efferent Modulation of Stimulus Frequency Otoacoustic Emission Fine Structure

Otoacoustic emissions, sounds generated in the inner ear, have become a convenient non-invasive tool to examine the efferent modulation of cochlear mechanics. Activation of the medial olivocochlear (MOC) efferents has been shown to alter the magnitude of these emissions. When the effects of efferent activation on the detailed spectral structures of these emissions have been examined, a shift of...

متن کامل

Study of the medial olivocochlear efferent system through otoacoustic emissions

The purpose of this study was to investigate the efferent medial olivocochlear system through the use of otoacoustic emissions and especially the modifications that occur at this level with age. The activity of outer hair cells (OHCs) (peripheral) and of the efferent medial olivocochlear (MOC) system (neural and central) was examined by means of distortion product otoacoustic emissions (DPOAEs)...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Journal of neurophysiology

دوره 107 7  شماره 

صفحات  -

تاریخ انتشار 2012