A Natural History Study in Pediatric Participants With Hearing Loss Due to OTOF, GJB2, or GJB2/GJB6 Mutations

Inclusion Criteria: * Participant is no older than 7 years (inclusive) at the time of the parent/legal guardian signing the informed consent form (ICF) * Participant has 1 of the following genotypes and meets the associated audiologic criteria based on physiologic and/or behavioral measures of inner ear function: * Biallelic pathogenic or likely pathogenic OTOF mutations with severe to profound sensorineural hearing loss (SNHL; ≥ 85 dB HL) and confirmed presence of OAEs * Biallelic pathogenic and truncating GJB2 mutation(s) with moderate or moderately-severe SNHL (≤41 to \<71 dB HL) * Digenic pathogenic or likely pathogenic mutations in GJB2 and GJB6 genes with mild or worse SNHL (\>26 dB HL) * Participant has at least 1 ear that has not received a cochlear implant (CI) Exclusion Criteria: * History of or active participation in an interventional trial related to hearing loss * History or presence of any other permanent/untreatable hearing loss conditions, including genetic conditions other than those involving biallelic OTOF or GJB2 mutations, or digenic GJB2/GJB6 mutations * History of treatment with ototoxic drugs