title: Time-frequency domain filtering of evoked otoacoustic emissions.
abstract: Time-domain filtering is a standard analysis technique, which is used to disentangle the two main vector components of the distortion product otoacoustic emission response, exploiting their different phase-frequency relation. In this study, a time-frequency filtering technique based on the continuous wavelet transform is proposed to overcome the intrinsic limitations of the time-domain filtering technique and to extend it also to the analysis of stimulus-frequency and transient-evoked otoacoustic emissions. The advantages of the proposed technique are first discussed on a theoretical basis, then practically demonstrated by applying it to the analysis of synthesized and real otoacoustic data. The results show that the time-frequency approach can be empirically optimized to get effective separation of the components of the otoacoustic response associated with either different generation mechanisms or different generation places. Focusing on a single component of the otoacoustic response with a given time-frequency signature may also improve significantly the signal-to-noise ratio, because the random noise contribution tends to be uniformly distributed on the time-frequency plane.
authors.affiliation: Department of Physics, Università di Roma Tor Vergata, Via della Ricerca Scientifica, 1, 00133 Roma, Italy. arturo.moleti@roma2.infn.it
authors.forename: Arturo
authors.initials: A
authors.lastname: Moleti
authors.forename: Federica
authors.initials: F
authors.lastname: Longo
authors.forename: Renata
authors.initials: R
authors.lastname: Sisto
mesh_terms: D000161:Acoustic Stimulation; D003051:Cochlea / Q000502:physiology*; D004424:Ear Canal / Q000502:physiology*; D005583:Fourier Analysis; D006801:Humans; D016014:Linear Models; D008954:Models, Biological; D017084:Otoacoustic Emissions, Spontaneous; D011930:Reaction Time; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D013018:Sound Spectrography; D013997:Time Factors