From crying to word production – observational study of an identical twin pair with severe hearing disorder

ABSTRACT

Background: There is overwhelming evidence that auditory processing plays an important role at the beginning of language development. This contradicts long held opinion by some researchers and parents that early vocal development is innate and does not require auditory input. Consequently, vocalizations such as cooing or pre-canonical babbling do not deviate in sensory-neural hearing impaired infants.

Method: Here we report twin data to contribute to this debate. Using repeated recordings of comfort utterances over the first 20 months, we objectively determined and compared the course of vocal development of a healthy identical twin pair with a profound neuro-sensory hearing disorder.

Results: Recordings four weeks after CI activation demonstrated an interesting phenomenon: vocal utterances seemed to re-vitalize primitive elements, i.e., we observed an apparent vocal ‘regression’.

Conclusion: The higher cognitive level of the 10-months-old girls at cochlear implantation compared to younger infants together with the more mature neural network for language development might be the essential reason for the quicker second passing of vocal stages.

KEYWORDS:

• Hearing
• CI
• babbling
• development
• twins

Disclosure statement

No potential conflict of interest was reported by the authors.