title: [Clinical value of distortion product otoacoustic emission (DPOAE) and their contralateral suppression effects].
abstract: OBJECTIVE
  The present paper aimed at examining the role of DPOAE and their contralateral suppressive effects in evaluation medial olivocochlear system (MOCS) function status in human.
  
  
  METHODS
  Seventeen subjects (34 ears) with normal hearing, 13 ears with cochlear hearing loss and 9 ears with retrocochlear hearing loss were studied on their DPOAE and contralateral suppression.
  
  
  RESULTS
  The results revealed that DPOAE amplitude significantly reduced in ears with cochlear hearing loss, contralateral suppression was smaller than normal ears but there was no significant difference between two groups. By contrast, DPOAE amplitude was much higher in ears with retrocochlear hearing loss than that in the other two groups. Contralateral suppression was significantly reduced or disappeared, and contralateral acoustic stimulus (CAS) even increased DPOAE amplitude in ears with retrocochlear hearing loss.
  
  
  CONCLUSIONS
  DPOAE and suppression induced by CAS can be used as an index of medial olivocochlear system (MOCS) function in patients with sensori-neuaral hearing loss, and can differentiate cochlear hearing loss from retrocochlear hearing loss. The tests of DPOAE and contralateral suppression may have much more advantages in clinical application over any other audiological test.
authors.affiliation: Department of Otolaryngology, Union Hospital, Tongji Medical University, Wuhan 430022.
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.forename: N
authors.initials: N
authors.lastname: Zhong
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001299:Audiometry; D003051:Cochlea / Q000503:physiopathology*; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009847:Olivary Nucleus / Q000503:physiopathology; D017084:Otoacoustic Emissions, Spontaneous