Pitch discrimination, melody identification, and timbre identification in CI users showed a wide range of perceptual abilities. The mean pitch change discrimination difference limen (DL) for the base frequency of 262 Hz (middle C) was 2.7 +/- 1.7 semitones: 4.4 +/- 4.2 semitones for 330 Hz (E4) and 8.1 +/- 3.0 semitones for 391 Hz (G4) in CI listeners. The DL widened as the base frequency increased. The melody identification test produced 21.1 +/- 21.7% correct answers, and the timbre identification test recorded 25.7 +/- 8.5% correct answers in CI listeners. Pitched percussion instruments (piano, guitar) were better for timbre identification. Speech performance scores had a positive correlation with the pitch discrimination DL (p < 0.05).

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Overall, the binaural performance was similar to each other between children who are fit with two CIs (CI + CI) and those who use bimodal stimulation (HA + CI) in most conditions. However, the bilateral CI group showed better speech perception than the bimodal CI group when babble was from the first device side (first CI side for bilateral CI users or CI side for bimodal listeners). Therefore, if bimodal performance is significantly below the mean bilateral CI performance on speech perception in babble, these results suggest that a child should be considered to transit from bimodal stimulation to bilateral CIs.