Prosodic modulation in the babble of cochlear implanted and normally hearing infants: A perceptual study using a visual analogue scale

This study investigates prosodic modulation in the spontaneous canonical babble of congenitally deaf infants with cochlear implants (CI) and normally hearing (NH) infants. Research has shown that the acoustic cues to prominence are less modulated in CI babble. However acoustic measurements of individual cues to prominence give incomplete information about prosodic modulation. In the present study, raters are asked to judge prominence since they simultaneously take into account all prosodic cues. Disyllabic utterances produced by CI and NH infants were presented to naive adult raters who had to indicate the degree and direction of prosodic modulation between syllables on a visual analogue scale. The results show that the babble of infants with CI is rated as having less prosodic modulation. Moreover, segmentally more variegated babble is rated as having more prosodic modulation. Raters do not perceive the babble to be predominantly trochaic, which indicates that the predominant stress pattern of Dutch is not yet apparent in the children’s productions.