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The mammalian auditory system contains descending pathways that originate in the cortex and relay at various intermediate levels before reaching the peripheral sensory organ of Corti. The last link in this chain consists of the olivocochlear bundle. The activity of this bundle can be measured through otoacoustic emissions, which are acoustic signatures of(More)
The activity of the medial olivocochlear bundle (MOCB) can be studied in humans through variations in the level of evoked otoacoustic emissions (EOAEs) elicited by contralateral acoustic stimuli (CAS). The present study sought to investigate how the activity of the MOC system at a given frequency, as measured through the contralateral suppression of(More)
It is well established that low-level broad band noise can elicit an amplitude decrease in evoked otoacoustic emissions recorded in the opposite ear. However, the influence of the temporal characteristics of the contralateral stimulus on this effect remains largely unknown. In the present study, otoacoustic emissions evoked by 60 dB SPL clicks were recorded(More)
The mammalian cochlea receives innervation from the central nervous system via two efferent systems: the lateral and the medial olivocochlear bundles. Advances in cochlear physiology have clarified the origins and terminations of these fibers. However, to date, while the functional significance of lateral efferents remains totally unknown, that of medial(More)
OBJECTIVE Contralateral suppression of the transient-evoked otoacoustic emissions (TEOAEs) provides a means of studying auditory efferent function, but the temporal dynamics of the reflex are not fully understood. The most fundamental parameter is the time-course of activation of contralateral suppression. The stimulus parameters are likely to be important;(More)
Evoked otoacoustic emissions (EOAEs) are assumed to be generated by outer hair cells (OHCs). It is now generally accepted that EOAEs represent a means of functional exploration of the active micromechanical properties of OHCs. Efferent fibers of the medial olivocochlear system (MOCS) are connected along the sides and the bases of OHCs. Some studies have(More)
To investigate the involvement of the medial olivocochlear system (MOCS) in outer hair cell (OHC) motility stabilization, evoked otoacoustic emissions (EOAEs) were recorded in 20 normal-hearing subjects and in eight vestibular-neurotomized subjects, successively in the presence and absence of low-intensity contralateral acoustic stimulation. Intrasubject(More)
In order to test the sensitivity of the human medial olivocochlear bundle (MOCB) to stimulus frequency fluctuations, changes in transient-evoked otoacoustic emission (TEOAE) amplitude induced by frequency modulated (FM) tones were measured in 18 normal-hearing subjects. The results revealed that TEOAE amplitude was reduced by contralateral FM tones at 40 dB(More)
Brainstem auditory evoked potentials (BAEPs) were recorded in 89 premature infants aged between 34 and 52 weeks. 47.2% had normal and 52.8% abnormal BAEPs in at least one ear. Seven risk factors were taken into account: birth weight lower than 1500 g, hypoxia, neurological damage, fetal pathology, associated malformation, the use of ototoxic drugs, and(More)
Variations in the amplitude of transiently evoked otoacoustic emissions (TEOAEs) produced by a contralateral complex tone were measured in 26 normal-hearing human subjects. TEOAEs were evoked using a 1-kHz tone pip at 60 dB SPL. The contralateral complex consisted of harmonic components with frequencies between 400 and 2000 Hz; it was presented at levels(More)