title: Influence of contralateral stimulation by two-tone complexes, narrow-band and broad-band noise signals on the 2f1-f2 distortion product otoacoustic emission levels in humans.
abstract: In order to test the frequency specificity of the efferent suppressive effect on otoacoustic emissions, changes in the 2f1-f2 distortion product otoacoustic emission (DPOAE) levels induced by contralateral stimuli of different spectra were measured in 10 normally hearing adults. Three types of contralateral stimuli were used: (i) a set of 6 pairs of pure tones with the same frequencies as used for DPOAE stimulation; (ii) 6 narrow-band noise signals with cut-off frequencies equal to the frequencies of the primary tones used for DPOAE stimulation; and (iii) broad-band noise with a bandwidth of 840-6,000 Hz. A small suppressive effect was observed mainly in the mid-frequency region. Broad-band noise was more effective at suppressing DPOAEs than narrow-band noises and two-tone complexes. Occasionally, small enhancements in DPOAE amplitudes were observed. Based on the results of this study, it is concluded that DPOAE changes induced by contralateral stimuli are not frequency-specific, and are too small to have routine clinical value.
authors.affiliation: Second ENT Department of the Silesian Medical Academy, Zabrze, Poland.
authors.forename: Grazyna
authors.initials: G
authors.lastname: Lisowska
authors.forename: Jacek
authors.initials: J
authors.lastname: Smurzynski
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Morawski
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Namyslowski
authors.forename: Rudolf
authors.initials: R
authors.lastname: Probst
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000293:Adolescent; D000328:Adult; D001306:Auditory Pathways / Q000502:physiology; D003056:Cochlear Nerve / Q000502:physiology; D004525:Efferent Pathways / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009433:Neural Inhibition; D009847:Olivary Nucleus / Q000502:physiology; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology*