title: Contralateral sound stimulation suppresses the compound action potential from the auditory nerve in humans.
abstract: BACKGROUND
  In the past decade, contralateral sound suppression of otoacoustic emissions has been extensively used to study the role of the medial olivocochlear efferent in humans. In most studies, the suppressive effect of contralateral sound stimulation was not greater than 2 to 4 dB. However, the relation between the degree of otoacoustic emission reduction and the neural auditory threshold is unknown.
  
  
  METHODS
  The current study investigates the effect of contralateral sound stimulation by measuring compound action potential response from the auditory nerve during retrosigmoid surgery in humans.
  
  
  RESULTS
  Although only a small number of subjects responded to contralateral sound stimulation, we report that efferent activation by contralateral sound stimulation results in 10 dB effective neural attenuation.
  
  
  CONCLUSIONS
  Together with previous otoacoustic emission measurements in humans, this result demonstrates that the suppressive effect of contralateral noise suppression is greater when measured with compound action potential than otoacoustic emissions, and that contralateral sound suppressive effect is at least as strong in humans as in animals.
authors.affiliation: Laboratoire d'Otoneurologie, Service ORL, CHU Gaston Doumergue, Nimes, France. rene.chabert@chu-nimes.fr
authors.forename: René
authors.initials: R
authors.lastname: Chabert
authors.forename: Jacques
authors.initials: J
authors.lastname: Magnan
authors.forename: Jean-Gabriel
authors.initials: JG
authors.lastname: Lallemant
authors.forename: Alain
authors.initials: A
authors.lastname: Uziel
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Puel
mesh_terms: D000161:Acoustic Stimulation / Q000295:instrumentation; D003056:Cochlear Nerve / Q000502:physiology*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D006801:Humans; D013016:Sound