Article
Suppression of Tone Burst Evoked Otoacoustic Emissions in Relation to Frequency Separation
Hearing Research
(2000)
Abstract
Tone burst evoked otoacoustic emissions (TBEOAEs) were measured for two tone bursts presented separately and as a two-tone burst complex to examine the linearity of TBEOAE generators for different frequency separations of the stimuli. The stimuli were: (a) tone bursts of 5-ms duration and center frequencies of 1, 1.5, 2 and 3 kHz; (b) complex stimuli with the 1-kHz tone burst combined digitally with each of the other specified tone bursts. Signals were delivered at 70 dB SPL using a non-linear processing method and at 60 dB SPL using a linear method to 21 ears of normally hearing adults. Spectra of TBEOAEs obtained with single-tone bursts were superimposed (composite) and compared to those of the two-tone burst complex. A close correspondence between the composite and complex spectra was present in all ears. However, the components on the higher-frequency slope of the 1-kHz spectral peak were reduced in the complex spectra obtained with a frequency separation of 0.5 kHz when compared to the corresponding composite spectra. The reduction was greater at a stimulus level of 70 dB SPL than with 60 dB SPL. The effect was smaller for a frequency separation of 1 kHz, and almost absent for the tone burst separation of 2 kHz. Thus, suppression leads to weak non-linear frequency superposition for higher-level, closely spaced stimuli.
Keywords
- Suppression,
- Frequency superposition,
- Cochlear mechanic,
- Transiently evoked otoacoustic emission
Disciplines
Publication Date
January 10, 2000
DOI
10.1016/S0378-5955(00)00144-1
Citation Information
Hiroshi Yoshikawa, Jacek Smurzynski and Rudolf Probst. "Suppression of Tone Burst Evoked Otoacoustic Emissions in Relation to Frequency Separation" Hearing Research Vol. 148 (2000) p. 95 - 106 ISSN: 0378-5955 Available at: http://works.bepress.com/jacek-smurzynski/4/