Identification performance by right- and left-handed listeners on dichotic CV materials

Normative data from 24 right-handed and 24 left-handed subjects were obtained for the dichotic consonant-vowel (CV) materials (pa, ta, ka, ba, da, and ga) recorded on the Veterans Affairs (VA) compact disc (CD) Tonal and Speech Materials for Auditory Perceptual Assessment, Disc 1.0. Identification performance by the two subject groups was significantly different. With the right-handed subjects, identification performances on the materials presented to the right ear (RE) were better than performances on the materials presented to the left ear (LE) by (1) 16.3 percent for simultaneous onsets (RE = 72.8%; LE = 56.5%), (2) 11.3 percent for the 90-msec right-ear lag (RE = 86.3%; LE = 75.0%), and (3) 8.7 percent for the 90-msec left-ear lag condition (RE = 85.8%; LE = 77.2%). In comparison to the right-handed subjects, the left-handed subjects exhibited a smaller right-ear advantage and more inter-subject variability. With the left-handed subjects, identification performances on the materials presented to the right ear also were better than performances on the materials presented to the left ear by (1) 1.7 percent for simultaneous onsets (RE = 62.9%; LE = 61.1%), (2) 2.8 percent for the 90-msec right-ear lag (RE = 75.0%; LE = 72.2%), and (3) 3.1 percent for the 90-msec left-ear lag condition (RE = 75.9%; LE = 72.9%). The results are similar to previous dichotic CV data and indicate that the CVs recorded on the VA-CD provide valid estimates of identification performance on the dichotic CV materials.