Swept-tone transient-evoked otoacoustic emissions

J Acoust Soc Am. 2010 Oct;128(4):1833-44. doi: 10.1121/1.3467769.

Abstract

Transient-evoked otoacoustic emissions (TEOAE) are responses generated within the inner ear in response to acoustic stimuli and are indicative of normal cochlear function. They are commonly acquired by averaging post-stimulus acoustic responses recorded near the eardrum in response to brief stimuli such as clicks or tone pips. In this study a new long duration stimulus consisting of a frequency swept tone is introduced for the acquisition of TEOAEs. Like stimulus frequency generated OAEs, swept-tone responses contain embedded OAEs. With swept-tone analysis, OAEs can be recovered by convolving it with a time reversed swept-tone signal resulting in time-compression. In addition, higher order nonlinear OAE responses were removed from the linear TEOAE. The results show comparable phase and time-frequency properties between the click and swept-tone evoked OAEs. Swept-tone acquisition of TEOAEs has beneficial noise properties, improving the signal to noise ratio by 6 dB compared to click evoked responses thus offering testing time savings. Additionally, swept-tone analysis removed synchronized spontaneous OAE activity from the recordings of subjects exhibiting such responses in conventional click TEOAEs. Since swept-tone stimulus consists of a single frequency component at any instantaneous moment, its analysis also provides for direct comparison with stimulus-frequency OAEs and click evoked OAEs.

Publication types

  • Comparative Study

MeSH terms

  • Acoustic Stimulation
  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Audiometry
  • Auditory Threshold
  • Cochlea / physiology*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Nonlinear Dynamics
  • Otoacoustic Emissions, Spontaneous*
  • Reaction Time
  • Sound Spectrography
  • Time Factors
  • Young Adult