title: Contralateral suppression of transient-evoked otoacoustic emissions in children with sickle cell disease.
abstract: OBJECTIVE
  In previous studies, otoacoustic emissions (OAEs) have been found to be larger in normal-hearing children with sickle cell disease (SCD). It was hypothesized that some dysfunction or reduction in the medial olivocochlear efferent suppression of outer hair cell activity was responsible for this phenomenon. To test this hypothesis, contralateral suppression of transient-evoked otoacoustic emissions (TEOAEs) was examined in children with and without SCD.
  
  
  METHODS
  Thirteen African American school-aged normal-hearing children with homozygous SCD and 13 age- and gender-matched control children participated. TEOAEs were obtained bilaterally with 80 dB peSPL nonlinear click stimuli. To examine contralateral suppression, TEOAEs were obtained with 60 dB peSPL linear click stimuli with and without a contralateral 65 dB SPL white noise suppressor.
  
  
  RESULTS
  Overall and half-octave band TEOAE levels were found to be larger in children with SCD relative to the normal control children (p < 0.05), consistent with previous reports of increased OAE levels. There was no significant difference (p > 0.05) in the absolute or proportional amount of TEOAE suppression as a function of group and ear. There were also no significant correlations or linear predictive relationships between TEOAE suppression and TEOAE level for either ear or group (p > 0.05).
  
  
  CONCLUSIONS
  These findings do not support the notion that increased OAE levels in children with SCD are a consequence of abnormal medial olivocochlear system function as assessed with contralateral suppression of TEOAEs.
authors.affiliation: Department of Communication Sciences and Disorders, East Carolina University, Health Sciences Building, East Carolina University, Greenville, NC 27858, USA. stuarta@ecu.edu
authors.forename: Andrew
authors.initials: A
authors.lastname: Stuart
authors.forename: June L
authors.initials: JL
authors.lastname: Preast
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000235:genetics / Q000503:physiopathology*; D001301:Audiometry, Pure-Tone; D001306:Auditory Pathways / Q000503:physiopathology; D001307:Auditory Perception / Q000502:physiology; D001309:Auditory Threshold / Q000502:physiology; D002648:Child; D017626:Cochlear Nucleus / Q000502:physiology*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D018072:Hair Cells, Auditory, Outer / Q000502:physiology; D006319:Hearing Loss, Sensorineural / Q000503:physiopathology*; D006720:Homozygote; D006801:Humans; D008297:Male; D009847:Olivary Nucleus / Q000502:physiology; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology*