Development of speech reception threshold materials for speakers of Taiwan Mandarin

The aim of this research was to develop, digitally record, evaluate, and equate speech audiometry materials that can be used to measure the speech reception threshold (SRT) in quiet for native speakers of Taiwan Mandarin. Familiar trisyllabic words were digitally recorded by male and female talkers of Taiwan Mandarin and subsequently evaluated by 20 native listeners with normal hearing at 14 intensity levels (-10 to 16 dB HL) in 2 dB increments. Using logistic regression, psychometric functions were calculated for all words. Twenty-eight words with comparatively steep psychometric functions were selected and digitally adjusted to match the mean subject pure-tone average (5.0 dB HL). This resulted in a list of words that are relatively homogeneous in threshold audibility and psychometric function slope. The mean slopes for the 28 selected male and female trisyllabic Taiwan Mandarin words were 11.3%/dB and 11.7%/dB, respectively.