Puttabasappa Manjula, Jawahar Antony, Keelara Shivaraju Sharath Kumar, Chinnaraj Geetha
(Department of Audiology, All India Institute of Speech and Hearing, Mysore, Mysore, India)
JHS 2015; 5(1): OA22-30
Standard word lists are required to assess an individual’s level of speech understanding. The material should comprise a number of lists and has to be in the listener’s native language. The aim of the present study was to develop and standardize a set of phonemically balanced word lists for adults in the Kannada language.
MATERIAL AND METHODS: Exactly 1200 bisyllabic Kannada words were collected from various sources and evaluated for familiarity. The words that were familiar (820 of them) were assessed for equivalency at –3 dB signal-to-noise ratio (SNR) to make sure that the words in the lists were of equal difficulty. Equivalency across the word lists were assessed, in quiet at four sensation levels, on 65 participants with normal hearing. Equivalency was also assessed on 100 participants with normal hearing in noise at –3 dB SNR.
RESULTS: The assessment of word equivalency revealed that 769 words had a score of around 50% identification at –3 dB SNR. These words were then used to construct 25 test lists each containing 25 words. Except for List 5, all other word lists were equivalent in quiet. The performance intensity function for phonemically balanced words in quiet was derived at 4 SLs for all the other 24 lists. Assessment of list equivalency in noise revealed that Lists 1, 4, 5, and 12 were significantly different from the other lists. After removing these four lists, the mean word recognition score was 46.04% (raw score) at –3 dB SNR in 100 individuals with normal hearing sensitivity.
CONCLUSIONS: The standardized 24 word lists in quiet and 21 word lists in noise can be used for adults in routine speech identification testing, assessment of hearing aid benefits, and for research that requires multiple word lists.
Keywords: Audiology, Speech Acoustics, Speech Intelligibility