Relaxation dynamics of spontaneous otoacoustic emissions perturbed by external tones. III. Response to a single tone at multiple suppression levels.
Murphy-WJ; Tubis-A; Talmadge-CL; Long-GR; Krieg-EF
J Acoust Soc Am 1996 Dec; 100(6):3979-3982
The relaxation dynamics of spontaneous otoacoustic emissions (SOAE) interacting with an external tone using a van der Pol limit cycle oscillator model interacting with multiple constant level external tones were described. Six data sets were collected using different levels of suppression. The waveforms consisted of four distinct transitions between the different signal conditions. All the waveforms exhibited a slight undershoot of the theoretical fit during the initial transition from unsuppressed to suppressed conditions. The dynamics of spontaneous emissions interacting with external stimuli may be inherent properties arising from the underlying mechanics responsible for generating spontaneous otoacoustic emissions. This theory may not fully describe the SOAE relaxation dynamics, but it further defines cochlear models which seek to stimulate otoacoustic emissions. The analysis has demonstrated that the dynamics of the interaction of an SOAE with a single frequency tone at multiple levels of suppression were adequately described by an isolated limit cycle oscillator interacting with an external tone. Additional fit parameters do improve the quality of the fit to more fully account for the behavior of the emission.
NIOSH-Author; Acoustical-measurements; Mathematical-models; Acoustic-vibration; Acoustic-signals; Biophysics; Noise-frequencies
Journal of the Acoustical Society of America