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This is the accepted version of the paper.This version of the publication may differ from the final published version. 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. Permanent repository link

Normally hearing (NH) infants are able to produce lexical stress in their first words, but congenitally hearing-impaired children with cochlear implants (CI) may find this more challenging, given the limited transmission of spectro-temporal information by the implant. Acoustic research has shown that the acoustic cues to stress in the first words of Dutch-acquiring CI infants are less pronounced (Pettinato et al. 2017). The present study investigates how listeners perceive lexical stress in the first words of CI and NH infants. Two research questions are addressed: (1) How successful are CI and NH children in implementing the prosodic cues to prominence? (2) Is the degree of stress in CI and NH words perceived to be similar?The stimuli used in this study are disyllabic words (n = 1089) produced by 9 infants with CI and 9 NH infants acquiring Dutch. The words were presented to adult listeners in a listening experiment, in which they assessed the stress pattern on a continuous visual analogue scale (VAS) which expresses to what extent syllables are perceived as stressed.The results show that listeners perceive typical word stress production in the first words of infants with CI. The words of CI and NH infants were rated in agreement with the target stress pattern as often, and trochaic words were rated more frequently as such than iambic words. Listeners more frequently perceive unstressed syllables in the first words of infants with CI. However, for the words that are perceived to be clearly stressed, the degree of word stress is comparable in the two groups, and both infant groups are perceived to produce more contrast between stressed and unstressed syllables in trochees than in iambs. It is concluded that that acoustic differences between CI and NH infants' stress production are not necessarily perceptually salient. Highlights• The present study investigates how listeners judge lexical stress in the first words of CI and NH infants on a visual analogue scale. • Words of infants with CI are as often rated in agreement with the target stress pattern as the words of NH infants. • Listeners more frequently perceive no stressed syllable in the first words of infants with CI as compared to the first words of NH infants. • It is concluded that acoustic differences between CI and NH infants' stress production are not necessarily perceptually salient.