The Unique Voice Profile of Children With Auditory Brainstem Implants: A Novel Study on Voice Onset Time
İsa Tuncay Batuk, Beyza Demirtaş Yılmaz, Merve Ozbal Batuk, Gonca Sennaroğlu, Levent SennaroğluPurpose:
A limited body of research has investigated temporal speech production parameters in children with auditory brainstem implants (ABIs). This study aimed to compare voice onset time (VOT) production profiles in pediatric users of unilateral cochlear implants (CIs), bilateral CIs, and ABIs with an age-matched normal-hearing (NH) control group.
Method:
Seventy native Turkish-speaking children (24 with NH, 17 with unilateral CI, 20 with bilateral CI, and nine with ABI) participated in the study. VOT values were acoustically measured from 18 real words containing initial voiced and voiceless stop consonants across different vowel contexts using Praat software.
Results:
Significant between-group differences were observed for both voiceless and voiced plosives. For voiceless plosives (requiring long-lag aspiration), all implant groups produced significantly shorter VOTs than their NH peers, with the ABI group demonstrating the shortest values. For voiced plosives (requiring true prevoicing), CI users deviated significantly from NH norms; remarkably, however, ABI users successfully achieved prevoicing, showing no significant difference from the NH group. Furthermore, within-group analyses revealed that the implant groups lacked the consistent vowel-driven anticipatory coarticulation observed in the NH group.
Conclusions:
Severe degradation of the auditory feedback loop affects VOT production differently across auditory device types. Children with ABIs exhibit a unique compensatory profile characterized by preserved temporal accuracy for low-frequency voiced targets but with significant deficits for high-frequency voiceless targets. For speech-language pathologists working in school settings, these findings underscore the necessity of designing device-specific and language-sensitive interventions—particularly targeting precise laryngeal coordination—to support speech intelligibility and phonological development in this clinical population.
Supplemental Material: