Development of phonologically-balanced and perceptually equivalent Singapore Mandarin word lists for word recognition test

Background Word recognition tests must be conducted in the native language of the listener to obtain valid word recognition scores. Existing Singapore Mandarin speech audiometry test materials that are disyllabic lack in sensitivity and are not phonologically balanced. Objective The purpose of this study was to address those limitations and develop a set of word lists for testing speakers of Singapore Mandarin. Methods The word lists were developed over three phases. (1) Frequently occurring words were chosen from a database consisting of subtitles from local Mandarin programmes, and subjected to familiarity rating by 50 native Singapore Mandarin speakers. (2) Phonologically balanced word lists were created and professionally recorded using words rated as familiar in phase 1. (3) Psychometric curves of words were obtained from 20 normal-hearing native speakers and word lists were analysed for perceptual equivalence. Results Sixteen phonologically balanced word lists consisting of 25 monosyllables each were created in phase 2. Eight of the 16 lists were found to be perceptually equivalent. Conclusion Word lists developed in this study addressed the limitations of existing Singapore Mandarin speech audiometry materials. The word lists need to be validated with normal-hearing and hearing-impaired Singapore Mandarin speakers before they can be used clinically.