Performance of Dichotic Digit Test by Inter-digit Intervals and Response Modes

Abstract

The purpose of this study aimed to investigate appropriate parameters for clinical use by measuring effects of inter-digit-intervals (IDIs) and response modes on the dichotic 3 digit test. The dichotic 3 digit tests were performed in four different IDI conditions (500, 750, 850, and 1,000 ms) in free-recall response mode and in three attention modes (Free recall, Precued Rt or Precued Lt) with a 750 ms IDI appearing in a performance of 70%. Twenty adults, 10 males and 10 females with normal hearing sensitivity participated. The results of this study were as follows: first, the dichotic 3 digit recognition performance was increased as IDI increased from 500 ms to 850 ms and decreased as IDI increased from 850 ms to 1,000 ms. Second, performances by response modes in 750 ms condition were measured that score of ear which was given cue were higher than opposite ear. Recognition scores of Free-recall, Precued-Rt, and Precued-Lt conditions were 69.00%, 93.75%, and 72.00% for the right ear and 65.75%, 64.75%, and 83.75% for the left ear, respectively. Also, ear advantages appeared 3.25% REA, 28.00% REA, and 11.75% LEA in Free-recall, Precued-Rt, and Precued-Lt conditions, respectively. Performances were also higher in Precued-recall conditions than in Free-recall condition. The results revealed that dichotic 3 digit recognition scores changed by IDIs and response modes. It showed that the 850 ms in IDI in free-recall mode was a useful parameter clinically applicable in dichotic 3 digit test. Moreover, the 750 ms paradigm of IDI and Precued recall of response modes can be useful in clinical setting.