Briana Rae and Dr. Richard Harris, Communication Disorders
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This study adds to the ongoing work of creating a system capable of administering accurate speech recognition threshold (SRT) tests to non-native English speakers. The SRT test helps in determining the brain’s ability to hear and understand speech. Bedke-Slade (2006) developed a SRT word list comprised of 28 words in the Taiwan Mandarin language which she recorded onto a compact disc. This word list, however, was not re-tested to ensure its performance matched the outcome predicted by Bedke-Slade. That’s where I came in.
I used the lists recorded by Bedke-Slade to test a new population of native Taiwan Mandarin speakers. I had three objectives in mind for this testing: (a) review how the mean SRT (for both male and female talker recordings) compared to the mean pure tone average (PTA) for test participants; (b) determine if the results from this study verify the predictions published by Bedke-Slade (2006); and (c) observe if the SRT obtained using the male talker recording differed from that obtained using the female talker recording.
The BYU Taiwan Mandarin speech audiometry materials CD was used to present stimuli during this study (Harris et al., 2006). This CD contains a custom-made program for general use in testing of speech audiometry; it further contains word lists specific to Taiwan Mandarin testing. Each of the 28 SRT words included on the CD are trisyllabic words that have gone through a series of native Taiwanese judges to determine they are adequately familiar and culturally sensitive to the average speaker of Taiwan Mandarin.
I used sixteen participants for data analysis. Each participant successfully completed an initial screening test to determine hear health and normal hearing. They were then familiarized with the 28 trisyllabic words and were given the speech recognition threshold test and the psychometric function test. The data was used to find averages and to form psychometric functions for each of the 28 trisyllabic Taiwan Mandarin words used in the word lists, both for the male and the female talkers. Those results were further compared to the results originally gathered by Bedke-Slade. The desired end was to have my results compare favorably with Bedke-Slade’s. A close match would allow for a confident recommendation to use the CD for clinical purposes. And that is basically what I found.
In a nut shell, this study provides evidence that (a) the SRT data obtained using the recorded Taiwan Mandarin word list can be used to verify PTA; (b) the psychometric functions reflected words that were slightly easier to hear than the predicted functions’ words due to a different PTA for each study; and (c) the difference between the SRT derived from male and female talkers is statistically insignificant. This means that the word list adequately performs its function of verifying the accuracy of the PTA; that the word list provides reliable results test after test; and that either the male or female talker can be used with equal accuracy and success. Therefore, the Taiwan Mandarin SRT word list is recommended for clinical use.
There are various exciting avenues that can be explored in future research. For example, one factor to consider when working with the Mandarin language is how tones affect the accuracy of the speech test’s representation of a client’s hearing impairment. Although much research on Mandarin tones has been done linguistically, further research on their clinical impact is warranted. There is also a potential need for the development of word lists for pediatric populations. The manner of word presentation and the words themselves would be different than what is found on more adult focused tests, such as this one. This study looked at the performance of those with normal hearing when presented with the Taiwan Mandarin SRT word list. Further research should naturally lead the clinician to evaluate the Taiwan Mandarin speech audiometry materials on a population of hearing impaired native Taiwanese patients, the target population of the CD. Further research can also be done to compare the relative merits of this test with other speech tests designed for non-native English speakers. And finally, an updated version of the word list could be created, eliminating some of the troublesome, lesser-known, or similar sounding words.
This research was conducted for a BYU Honors Thesis and was completed as part of the requirements to graduate with University Honors. As such, it was bound and placed in the Harold B. Lee Library, among other locations. Furthermore, I presented this research in poster form at the 2010 David O. McKay School of Education Mentored Research Conference. It is my hope that in the future it can also be published in a journal from my discipline.
Sources
- Bedke-Slade, K. (2006). Speech reception threshold materials for Taiwan Mandarin. (Unpublished master’s thesis). Brigham Young University, Provo, Utah, USA.
- Harris, R. W., Nissen, S., Slade, K. B., & Dukes, A. J. (2006). Taiwan Mandarin speech audiometry materials. [Compact Disc]. Provo, UT: Brigham Young University.