Why repetition? Repetitive babbling, auditory feedback, and cochlear implantation

Area of Science:

• Developmental Psychology
• Speech-Language Pathology
• Neuroscience

Background:

• Repetitive vocalizations (babbling) emerge around 7-8 months in hearing infants.
• The role of auditory input in developing vocal repetition is not fully understood.
• Cochlear implantation offers a potential pathway for auditory feedback in infants with hearing loss.

Purpose of the Study:

• To investigate the impact of cochlear implants on repetitive vocalizations in infants with profound hearing loss.
• To explore the reasons behind the emergence of vocal repetition.
• To understand the developmental transition from nonlinguistic to linguistic vocalization.

Main Methods:

• A new measure of vocal repetition was used.
• Participants included 16 infants with profound hearing loss and 27 hearing infants.
• Data were collected at multiple time points before and after cochlear implantation.

Main Results:

• Repetitive vocalizations were infrequent in infants with hearing loss before cochlear implantation.
• Four months post-implantation, infants showed comparable levels of vocal repetition to hearing peers.
• Both the occurrence of repetitive vocalizations and repetitions per vocalization increased significantly.

Conclusions:

• Cochlear implantation facilitates the development of vocal repetition in infants with profound hearing loss.
• Repetition appears to be a mechanism for vocal exploration and auditory-motor integration.
• Findings support the hypothesis that auditory feedback is critical for developing neural connections for speech production and perception.