title: The generation mechanisms and repeatability of 2F1-F2 distortion product otoacoustic emissions: study on normally hearing subjects.
abstract: The 2F1-F2 distortion product otoacoustic emission (DPOAE) is considered to consist of two generation mechanisms, the so-called place-fixed and wave-fixed mechanisms, depending on the frequency ratio F2/F1. The general assumption is that for a small frequency ratio there is a predominantly place-fixed emission mechanism, while with a larger frequency ratio there is a predominantly wave-fixed mechanism. There is also a lack of published data on the repeatability of the two components when separated. One aim of this study was therefore to identify the wave-fixed and place-fixed components of the 2F1-F2 DPOAE using a time-window separation method. The second aim was to quantify the test-retest repeatability of the separated 2F1-F2 DPOAE components in a group of normally hearing subjects. Results confirmed the presence of wave-fixed and place-fixed components for 2F1-F2 and a predominance of place or wave-fixed DPOAE as a function of frequency ratio. This pattern varied somewhat among subjects. Moreover, regardless of which component was stronger for any F2/F1, both components were highly repeatable across time within individual ears.
authors.affiliation: Ist. di Ingegneria Biomedica, CNR, Milano, Italy. marta.parazzini@polimi.it
authors.forename: M
authors.initials: M
authors.lastname: Parazzini
authors.forename: H K
authors.initials: HK
authors.lastname: Wilson
authors.forename: S
authors.initials: S
authors.lastname: Bell
authors.forename: G
authors.initials: G
authors.lastname: Tognola
authors.forename: P
authors.initials: P
authors.lastname: Ravazzani
authors.forename: M E
authors.initials: ME
authors.lastname: Lutman
mesh_terms: D000465:Algorithms; D016477:Artifacts; D001307:Auditory Perception / Q000502:physiology*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D006320:Hearing Tests / Q000379:methods*; D006801:Humans; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology*; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity