title: Test/retest repeatability of effect contralateral acoustic stimulation on the magnitudes of distortion product ototacoustic emissions.
abstract: OBJECTIVE
  Contralateral inhibition of distortion product otoacoustic emissions (DPOAE) has become an important tool to assess the functioning of the medial olivocochlear efferents in humans. However, before this measurement can be applied clinically, the test/retest repeatability needs to be established. Therefore, the current study aimed at evaluating intra- and intersession test/retest repeatability of contralateral inhibition of DPOAE at 2f(1) -f(2) .
  
  
  METHODS
  Prospective Test/Retest Reliability Study.
  
  
  METHODS
  Contralateral inhibition of DPOAE magnitudes were measured in the right ear of 24 adult male participants. To assess the intrasession repeatability, measurements were repeated without altering the position of the DPOAE probe (single-probe-fit). To assess intersession reliability, measurements were repeated on 8 different days (multiple-probe-fit). Repeatability of inhibition of DPOAE magnitudes was evaluated by Cronbach's alpha, interclass correlations, standard error of measurement, and its 95% confidence interval and smallest detectable difference.
  
  
  RESULTS
  DPOAE magnitudes were highly stable and repeatable across different recording sessions. However, test/retest reliability coefficients of DPOAE inhibition magnitudes were less than satisfactory for all the frequencies, in both single-probe-fit and multiple-probe-fit modes.
  
  
  CONCLUSIONS
  Results of the present study showed that contralateral inhibition magnitudes of DPOAEs varied considerably, even though DPOAEs magnitudes remained essentially the same across different recording sessions. As reliability is an essential aspect of any clinical procedure, it is suggested that at present contralateral inhibition of DPOAEs should not be used clinically to evaluate the medial efferent system. Laryngoscope, 2012.
authors.affiliation: Department of Audiology, All India Institute of Speech and Hearing, Manasagangothri, Mysore, India. ajithkumar18@gmail.com
authors.forename: U Ajith
authors.initials: UA
authors.lastname: Kumar
authors.forename: Raksha
authors.initials: R
authors.lastname: Methi
authors.forename: M C
authors.initials: MC
authors.lastname: Avinash
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D006801:Humans; D008297:Male; D008875:Middle Aged; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted