Thai phonetically balanced word recognition test: Reliability evaluations and bias and error analysis
Adirek Munthuli, Chutamanee Onsuwan, Charturong Tantibundhit, Krit Kosawat · The Journal of the Acoustical Society of America · 2014
Word recognition score (WRS) is one of the measuring techniques used in speech audiometry, a part of a routine audiological examination. The test’s accuracy is crucial and largely depends on the test materials. With emphasis on phonetic balance, test-retest reliability, inter-list equivalency, and symmetrical phoneme occurrence, Thammasat University Phonetically Balanced Word Lists 2014 (TU PB’14) were created with five different lists, each with 25 Thai monosyllabic words. TU PB’14 reflects Thai phoneme distribution based on large-scale written Thai corpora, InterBEST [1]. To evaluate its validity and test-retest reliability, the lists were given at five intensity levels (15–55 dB HL) in test and retest sessions to 30 normal-hearing subjects. The differences in performance between the two sessions are not significantly large and correlation coefficients at the linear regions are all positive. Analysis of listeners’ errors, including sequence recurrences, was carried out. Errors occurred predominantly in the case of initials, followed by finals and lexical tones. Confusion patterns of initials, finals, and tones are in line with those found for Thai speech sounds in noise condition. Interestingly, vowels are found to be most resistant to confusion. Finally, possible effect of lexical frequency is examined and discussed.