When a child is diagnosed with hearing impairment, early intervention should be provided to avoid language deprivation and its consequences. This study investigates the contribution of two spoken language rehabilitation approaches to speech development in children with cochlear implants (CI) using a nonword repetition task. Cued Speech (CS) is a multisensory communication tool, facilitating speech perception by providing access to all phonemes. Auditory Verbal Therapy (AVT) is a hearing-focused method, training auditory skills to boost speech perception. Earlier studies have reported that CS and AVT improve phonological skills in a picture-naming task. In this study, using a nonword repetition task, we show that the number of consonant and vowel errors is higher in children with CI than in typically-hearing peers, independently of the rehabilitation method. Therefore, children with CI may have hidden speech processing difficulties that remain undetected in lexical speech tasks but can be revealed by nonword repetition.