Document Detail


Activation of medial olivocochlear efferent system in humans: influence of stimulus bandwidth.
MedLine Citation:
PMID:  10675639     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
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 tone-pip EOAEs, depends on the bandwidth of the contralateral stimulus. EOAEs were recorded in 155 normal-hearing subjects, successively with and without contralateral stimuli whose bandwidth, center frequency and level were systematically varied. We showed a clear dependence of contralateral EOAE suppression on bandwidth demonstrating increased suppression with increased bandwidth over about two octaves around the center frequency of the noise. This effect was obtained irrespective of whether contralateral noise energy was kept constant independently of bandwidth or not, which indicates a role of bandwidth per se in contralateral EOAE suppression. Results are interpreted in terms of a simple model of MOCB activation mechanisms including peripheral bandpass filtering, within-channel compression and across-channel spatial summation by the afferent paths. Complementary experiments suggested a greater effectiveness of increases in bandwidth on the upper than on the lower side and of frequency components akin to or remote from the test frequency than of intermediate bands. Finally, these results were complemented by detailed spectrum analyses of the EOAE level variations induced by the different noises, which revealed that whilst noise components close to or remote from the center frequency generally attenuated EOAE level, intermediate components could in some cases lead to a relative increase in EOAE level. These results can further be explained by assuming different positive and negative weights on the inputs to the spatial summation process depending on their position relative to the center frequency.
Authors:
S Maison; C Micheyl; G Andéol; S Gallégo; L Collet
Related Documents :
17525229 - Macular pigment: a test of the acuity hypothesis.
15139639 - Spectral integration of synchronous and asynchronous cues to consonant identification.
16712229 - Quantum lithography with classical light.
3980869 - Gap detection in chinchillas with temporary high-frequency hearing loss.
2229669 - Uncertainty about the correlation among temporal envelopes in two comodulation tasks.
3182409 - Components of monaural envelope correlation perception.
18508139 - Asynchronous normal regional left ventricular function assessed by speckle tracking ech...
21264709 - Magnitude judgments of loudness change for discrete, dynamic, and hybrid stimuli.
3660649 - Simulation of responses of spectrally-opponent neurones in the macaque lateral genicula...
Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  Hearing research     Volume:  140     ISSN:  0378-5955     ISO Abbreviation:  Hear. Res.     Publication Date:  2000 Feb 
Date Detail:
Created Date:  2000-03-24     Completed Date:  2000-03-24     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7900445     Medline TA:  Hear Res     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  111-25     Citation Subset:  IM    
Affiliation:
Université Claude Bernard Lyon 1, Laboratoire 'Neurosciences et Systèmes Sensoriels' UPRESA CNRS 5020, Lyon, France. smaison@olfac.univ-lyon1.fr
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Acoustic Impedance Tests
Acoustic Stimulation
Adolescent
Adult
Analysis of Variance
Audiometry, Pure-Tone
Cochlea / innervation,  physiology*
Cochlear Microphonic Potentials / physiology
Evoked Potentials, Auditory / physiology
Female
Functional Laterality
Humans
Male
Neurons, Efferent / physiology*
Noise
Olivary Nucleus / physiology*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Evidence for multiple DPOAE components based upon group delay of the 2f(1)-f(2) distortion in the ge...
Next Document:  Glycine induced calcium concentration changes in vestibular type I sensory cells.