a Study in Subjects With Otoferlin Mutation-related Hearing Loss Using RNA Base-eDiting Therapy(SOUND)

Inclusion Criteria: * Male or females between 1 and 16 years of age at the time the subject/parent/legal guardian signs the informed consent form. * Willing to adhere to the protocol as evidenced by written informed consent or parental permission and subject assent. * Molecular diagnosis of biallelic mutations in the OTOF gene with at least one mutation being p.Q829X through collected blood samples at screening; * Based on auditory brainstem response (ABR), clinically diagnosed sensorineural hearing loss (SNHL) with the following hearing thresholds: severe (65 dB ≤ hearing threshold \< 80 dB) or profound (80 dB ≤ hearing threshold \< 95 dB) or complete (hearing threshold ≥ 95 dB) hearing loss in both ears. * Acceptable hematology, clinical chemistry, and urine laboratory parameters. Exclusion Criteria: * Pre-existing other hearing-loss conditions that would preclude the planned surgery or interfere with the interpretation of study endpoints or complications of surgery. * Presence of cochlear implants in the study ear. * Complicating systemic diseases or clinically significant abnormal baseline laboratory values. * Complicating systemic diseases would include those in which the disease itself, or the treatment for the disease, can alter hearing function. * Prior participation in clinical study with an investigational drug within the past six months. * Prior gene therapy treatments. * Any condition which leads the investigator to believe that the participant cannot comply with the protocol requirements or that may place the participant at an unacceptable risk for participation.