Development of SC-10: A psychometrically equivalent Singapore Mandarin disyllabic word list for clinical speech audiometry use

摘要

Objective::The aim of this study is to develop and evaluate a set of psychometrically equivalent disyllabic wordlist(SC-10)in Singapore Mandarin for clinical use.Study design::A preliminary set of 1000 words were obtained from a dictionary of frequently used words by Singapore students.Ten native judges rate the familiarity level of each word.This is followed by a face-to-face public survey to rank the shortlisted word set from most to least familiar.The final 108 disyllabic words were recorded by a native female talker.20 normal hearing subjects were used to obtain the percentage of correct word recognition at 24 intensity levels(-10 dB HL to 26 dB HL in 2 dB increment).Psychometric function slopes were calculated for each word.100 words were eventually chosen and assigned into ten 10-word lists based on a psychometric balancing protocol.Minor digital adjustments were made to the intensity of each wordlist to improve their auditory homogeneity.Results::The calculated regression slopes in the psychometric functions for the ten lists are between 8.0 and 9.8%/dB.Single factor ANOVA analysis showed no significant difference in both the mean intensity required to obtain 50%recognition score(f=0.109,df=9,p=0.999)and the slopes of the psychometric functions(f=0.078,df=9,p=0.999)between the ten word lists.List validation on 25 normal hearing participants(PTA=11.0 dB HL,SD=4.3)showed a mean speech recognition threshold(SRT)of 9.3 dB HL(SD=3.5)and regression slope of 8.395%/dB.Quadratic regression analysis showed a positive correlation(r^(2)=0.923)between presentation level and word recognition score(WRS).The difference between PTA and SRT of each subject all fall within the clinically acceptable difference of 10 dB HL.Test-retest reliability,carried out on 20 subjects at three levels(SRT-5,SRT,and SRT+5 dB),showed no significance difference between word recognition score when the same participant is tested again at the same intensity level using a different wordlist.Conclusion::All in all,it shows that the SC-10 speech materials are valid for clinical use for Mandarin speech audiometry in Singapore.