Evaluation of Difference in Performance of Young Adults in Dichotic Digit Test in Tamil and Dichotic Consonant Vowel Test

Dichotic listening has been defined as the simultaneous stimulation of both ears and has been used to evaluate a listener’s binaural integration/separation ability. Dichotic tests are available in various languages and use varied stimuli. The study aimed to evaluate the differential performance of Tamil-speaking young adults in two tests of dichotic perception namely Dichotic Consonant Vowel (DCV) test and Dichotic Digit Test in Tamil (DDT-T).

Sixty adults with normal hearing aged 18 to 35 years were the participants of the study. All the young adults were native speakers of the Tamil language without significant auditory history. DCV and DDT-T were administered in randomized order at 50 dB SL (re: SRT) in free recall condition. The participants were instructed to respond orally and the responses were noted.

Better performance was observed in dichotic digit compared to DCV test for all participants. This was attributed to the higher number of cues available in DDT-T. Further, error analyses of participants’ responses revealed that voicing errors were higher with the highest errors in the identification of unvoiced consonant /ta/ in both ears. The reason for this could be the lack of contextual cues in DCV test for Tamil-speaking individuals to interpret the voicing feature of a consonant.

It can be concluded that DDT-T was more useful in assessing binaural integration ability of native Tamil speakers compared to DCV. It is recommended to be used in the behavioral test battery for evaluating auditory processing disorder in native Tamil speakers.