title: Comparison of 2f1-f2 DPOAE and 2f2-f1 DPOAE fine structure in young and middle-aged adults.
abstract: OBJECTIVE
  The 2f2-f1 DPOAE is not as popular as the 2f1-f2 DPOAE in the clinical realm as it is not as robust. However, it does have an advantage of being a predominantly reflection emission. The reflection component has been found to be sensitive to cochlear damage. Our objective was to compare the two types of DPOAE to track subtle changes due to aging.
  
  
  METHODS
  We used the most suitable stimulus parameters to record the fine structures of 2f2-f1 DPOAE and 2f1-f2 DPOAE for comparison in two groups of individuals.
  
  
  METHODS
  Young adults and middle-aged adults with normal hearing sensitivity participated in the experiment. Both ears of all participants were tested.
  
  
  RESULTS
  Although reductions were noted in the both types of DPOAE in the middle-aged participants compared with the young adults, the decrease in amplitude of the 2f2-f1 DPOAE was found to be statistically significant. This corresponded with statistically significant reductions in the reflection component of the 2f1-f2 DPOAE. Reductions in the 2f2-f1 DPOAE were found with both, high-level and low-level primaries.
  
  
  CONCLUSIONS
  These results highlight the advantages of analysing fine structure data of the 2f2-f1 DPOAE to track subtle cochlear changes in response to aging.
authors.affiliation: * Department of Speech-Language-Hearing Sciences, University of Minnesota , Minneapolis , USA.
authors.forename: Aparna
authors.initials: A
authors.lastname: Rao
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Tusler
authors.forename: Audrey
authors.initials: A
authors.lastname: Formo
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000375:Aging; D001299:Audiometry; D001309:Auditory Threshold; D003051:Cochlea / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D017084:Otoacoustic Emissions, Spontaneous; D055815:Young Adult