Full metadata
Title
Using swept tones to evoke stimulus frequency otoacoustic emissions with in-situ calibration
Description
Otoacoustic emissions (OAEs) are soft sounds generated by the inner ear and can be recorded within the ear canal. Since OAEs can reflect the functional status of the inner ear, OAE measurements have been widely used for hearing loss screening in the clinic. However, there are limitations in current clinical OAE measurements, such as the restricted frequency range, low efficiency and inaccurate calibration. In this dissertation project, a new method of OAE measurement which used a swept tone to evoke the stimulus frequency OAEs (SFOAEs) was developed to overcome the limitations of current methods. In addition, an in-situ calibration was applied to equalize the spectral level of the swept-tone stimulus at the tympanic membrane (TM). With this method, SFOAEs could be recorded with high resolution over a wide frequency range within one or two minutes. Two experiments were conducted to verify the accuracy of the in-situ calibration and to test the performance of the swept-tone SFOAEs. In experiment I, the calibration of the TM sound pressure was verified in both acoustic cavities and real ears by using a second probe microphone. In addition, the benefits of the in-situ calibration were investigated by measuring OAEs under different calibration conditions. Results showed that the TM pressure could be predicted correctly, and the in-situ calibration provided the most reliable results in OAE measurements. In experiment II, a three-interval paradigm with a tracking-filter technique was used to record the swept-tone SFOAEs in 20 normal-hearing subjects. The test-retest reliability of the swept-tone SFOAEs was examined using a repeated-measure design under various stimulus levels and durations. The accuracy of the swept-tone method was evaluated by comparisons with a standard method using discrete pure tones. Results showed that SFOAEs could be reliably and accurately measured with the swept-tone method. Comparing with the pure-tone approach, the swept-tone method showed significantly improved efficiency. The swept-tone SFOAEs with in-situ calibration may be an alternative of current clinical OAE measurements for more detailed evaluation of inner ear function and accurate diagnosis.
Date Created
2012
Contributors
- Chen, Shixiong (Author)
- Bian, Lin (Thesis advisor)
- Yost, William (Committee member)
- Azuma, Tamiko (Committee member)
- Dorman, Michael (Committee member)
- Arizona State University (Publisher)
Topical Subject
Resource Type
Extent
ix, 120 p. : ill. (some col.)
Language
eng
Copyright Statement
In Copyright
Primary Member of
Peer-reviewed
No
Open Access
No
Handle
https://hdl.handle.net/2286/R.I.14711
Statement of Responsibility
by Shixiong Chen
Description Source
Retrieved on Dec. 31, 2012
Level of coding
full
Note
thesis
Partial requirement for: Ph.D., Arizona State University, 2012
bibliography
Includes bibliographical references (p. 91-102)
Field of study: Speech and hearing science
System Created
- 2012-08-24 06:20:01
System Modified
- 2021-08-30 01:47:47
- 3 years 2 months ago
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