Otoacoustic emissions at different click intensities: invariant and subject-dependent features

• Published in: Journal of applied physiology (1985) Vol. 95; no. 6; pp. 2299 - 2305
• Main Authors: Zimatore, Giovanna, Giuliani, Alessandro, Hatzopoulos, Stavros, Martini, Alessandro, Colosimo, Alfredo
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Am Physiological Soc 01.12.2003; American Physiological Society
• Subjects: Acoustic Stimulation; Adult; Algorithms; Anatomy & physiology; Audiology; Biological and medical sciences; Diagnosis, Differential; Ears & hearing; Evoked Potentials, Auditory - physiology; Female; Fourier Analysis; Fundamental and applied biological sciences. Psychology; Hearing Loss, Conductive - diagnosis; Hearing Loss, Conductive - physiopathology; Hearing Loss, Sensorineural - diagnosis; Hearing Loss, Sensorineural - physiopathology; Humans; Nonlinear Dynamics; Principal Component Analysis; Human; Vertebrata; Hearing; recurrence quantification analysis; Mammalia; Otoacoustic emission; hearing physiology; Intensity; click-evoked otoacoustic emissions; determinism
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/japplphysiol.00667.2003

1 Department of Human Physiology and Pharmacology, University of Rome "La Sapienza," and 2 Istituto Superiore di Sanità, 00185 Rome; and 3 Audiology Department and Center of Bioacoustics, University of Ferrara, 44100 Ferrara, Italy Submitted 30 June 2003 ; accepted in final form 16 August 2003 A study of click-evoked otoacoustic emissions (CEOAEs) elicited at stimulation intensities from 35 to >80 dB was carried out by recurrence quantification analysis on signals from both normal and hearing-impaired subjects. In normal subjects, a clear scaling of determinism with increasing stimulation intensity was observed in the click intensity range from 41 to 59 dB. Outside that range and, in particular, above its upper end, subject-dependent features appeared in the form of different maximal levels of determinism. A comparative analysis of responses from hearing-impaired subjects with conductive hearing losses and sensorineural hearing losses suggested that the principal contributor to this behavior is the middle ear and allowed us to discriminate the two pathologies solely on the basis of CEOAEs. These observations are consistent with a simple phenomenological model of the auditory periphery in which different functional modules are sequentially recruited at increasing stimulus intensities, with a consequent rise in CEOAE coherence. hearing physiology; click-evoked otoacoustic emissions; recurrence quantification analysis; determinism Address for reprint requests and other correspondence: A. Colosimo, Dept. of Human Physiology and Pharmacology, Univ. of Rome "La Sapienza", P. le A. Moro 5, 00185 Roma, Italy (E-mail: colosimo{at}caspur.it ).