Matching Items (2)
Filtering by
- All Subjects: psychology
- All Subjects: Tempo
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.
ContributorsChen, Shixiong (Author) / Bian, Lin (Thesis advisor) / Yost, William (Committee member) / Azuma, Tamiko (Committee member) / Dorman, Michael (Committee member) / Arizona State University (Publisher)
Created2012
Description
Tempo control is a crucial part of musicianship that can provide an obstacle for novice musicians. The current study examines why novice percussionists increase their playing tempo when they increase their loudness (in music, loudness is referred to as dynamics). This study tested five hypotheses: 1) As actual tempo changes, listeners perceive that the tempo is changing; 2) There is a perceptual bias to perceive increases in acoustic intensity as also increasing in tempo; 3) All individuals, regardless of percussion experience, display the bias described in hypothesis 2; 4) Unskilled or non-percussionists increase or decrease produced tempo as they respectively increase or decrease loudness; and 5) Skilled percussionist produce less change in tempo due to changes in loudness than non-percussionists. In Experiment 1, percussionists and non-percussionists listened to metronome samples that gradually change in intensity and/or tempo. Participants identified the direction and size of their perceived tempo change using a computer mouse. In Experiment 2, both groups of participants produced various tempo and dynamic changes on a drum pad. Our findings support that both percussionists and non-percussionists, to some extent, display a perceptual bias to perceive tempo changes as a function of intensity changes. We also found that non-percussionists altered their tempo as a function of changing dynamic levels, whereas percussionists did not. Overall, our findings support that listeners tend to experience some integrality between perceptual dimensions of perceived tempo and loudness. Dimensional integration also persists when playing percussion instruments though experience with percussion instruments reduces this effect.
ContributorsJohnson, Adam Gregory (Author) / McBeath, Michael (Thesis director) / Glenberg, Arthur (Committee member) / Yost, William (Committee member) / Barrett, The Honors College (Contributor) / Department of Psychology (Contributor)
Created2014-05