Comparison of the South African Spondaic and the CID W-1 wordlists for measuring speech recognition threshold

Abstract

INTRODUCTION. The Central Institute for the Deaf published Auditory Tests W-1 (CID W-1) spondaic wordlist was developed in the USA in 1947 and 1952. Certain American-English words contained in the wordlist are unfamiliar to many South Africans, even English first language (EFL) speakers, but particularly those who use English as a second language (ESL). Familiarity with spondaic words is one of the most important qualities of the test items used to determine Speech Recognition Threshold (SRT). OBJECTIVES. The aim of this study was to compare the SRT results obtained with the English South African Spondaic (SAS) wordlist developed by Durrant (2006) and the English CID W-1 spondaic wordlist when measuring the SRT of adult ESL speakers in South Africa. Method. Audiometric Pure Tone Average (PTA) and SRT measurements were obtained for 101 (197 ears) ESL participants with normal hearing or a minimal hearing loss <26 dBHL (mean age 33.3). PTA/SRT correlations were compared when using the SAS wordlist (groups one and two), as well as either the ‘less familiar’ CID W-1 (group one) or ‘more familiar’ CID W-1 (group two), in a mixed matched group design. RESULTS. A Pearson correlation analysis revealed a significant and positive correlation for all three wordlists. The Pearson correlation analysis revealed a strong PTA/SRT correlation when using the South African Spondaic (SAS) wordlist (right ear: 0.65; left ear 0.58) and the ‘more familiar’ words from the CID W-1 wordlist (right ear: 0.63; left ear: 0.56). The use of the ‘less familiar’ words from the CID W-1 wordlist revealed weak correlations (right ear: 0.30; left ear: 0.32). Paired sample T-tests indicated a statistically significantly stronger PTA/SRT correlation when the SAS wordlist was used, rather than either of the CID W-1 wordlists, at a 95% level of confidence. CONCLUSIONS. The use of the SAS wordlist yields a stronger PTA/SRT correlation than the use of the CID W-1 wordlist, when performing SRT testing as part of the speech audiometry battery on South African ESL speakers with normal hearing, or minimal hearing loss <26 dBHL.