Auditory Brainstem Implant (ABI) in Children With No Cochleae or Auditory Nerves

Inclusion Criteria: Group 1: Prelinguistic hearing loss (birth-5 years; age at implantation of ABI 18 months-5 years) • Pre-linguistic hearing loss (birth-5 yrs.; age at ABI 18 months-5yrs) with both: * MRI +/- CT evidence of one of the following: * Cochlear nerve deficiency * Cochlear aplasia or severe hypoplasia * Severe inner ear malformation * Post-meningitis ossification * When a cochlea is present or patent, lack of significant benefit from CI despite consistent use (\>6 mo.) * No or limited speech perception ability (limited to pattern perception on closed set testing materials using the CI) * Lack of progress in auditory skills development Group 2: Post-linguistic hearing loss (\<21 yrs. of age) * Post-linguistic hearing loss (\<21 yrs. of age) with: * Loss or lack of benefit from appropriate CI without the possibility for revision or contralateral implantation. Examples might include: * Post-meningitis ossification * Bilateral temporal bone fractures with cochlear nerve avulsion * Failed revision CI without benefit * Previously developed open set speech perception and auditory-oral language skills * No medical contraindications * Willing to receive the appropriate meningitis vaccinations * No or limited cognitive/developmental delays. * Strong family support * Reasonable expectations from parents/guardians including a thorough understanding: * of potential benefits and limitations of ABI * of parental role in rehabilitation …