title: On the spatial distribution of the reflection sources of different latency components of otoacoustic emissions.
abstract: The experimental observation of long- and short-latency components in both stimulus-frequency and transient-evoked otoacoustic emissions admits a comprehensive explanation within the coherent reflection mechanism, in a linear active transmission-line cochlear model. A local complex reflectivity function associated with roughness was defined and analyzed by varying the tuning factor of the model, systematically showing, for each frequency, a multiple-peak spatial structure, compatible with the observed multiple-latency structure of otoacoustic emissions. Although this spatial pattern and the peak relative intensity changes with the chosen random roughness function, the multiple-peak structure is a reproducible feature of different "digital ears," in good agreement with experimental data. If one computes the predicted transmission delays as a function of frequency and position for each source, one gets a good match to the latency-frequency patterns that are directly computed from synthesized otoacoustic spectra using time-frequency analysis. This result clarifies the role of the spatial distribution of the otoacoustic emission sources, further supporting the interpretation of different-latency otoacoustic components as due to reflection sources localized at different places along the basilar membrane.
authors.affiliation: Dipartimento Igiene del Lavoro, INAIL (Italian Workers Compensation Authority) Research, Via Fontana Candida 1, 00040 Monte Porzio Catone, Rome, Italy.
authors.forename: Renata
authors.initials: R
authors.lastname: Sisto
authors.affiliation: Dipartimento di Fisica, Università di Roma "Tor Vergata" Via della Ricerca Scientifica 1, 00133 Rome, Italy.
authors.forename: Arturo
authors.initials: A
authors.lastname: Moleti
authors.affiliation: Eaton-Peabody Laboratory of Auditory Physiology, Massachusetts Eye and Ear Infirmary, 243 Charles Street, Boston, Massachusetts 02114.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Shera
mesh_terms: D000161:Acoustic Stimulation; D001309:Auditory Threshold; D003051:Cochlea / Q000294:innervation*; D003198:Computer Simulation; D006801:Humans; D016014:Linear Models; D008962:Models, Theoretical; D017084:Otoacoustic Emissions, Spontaneous; D011930:Reaction Time; D013997:Time Factors