A Comparative Analysis of Speech Perception Between Cochlear Implant Patients and DFNB9 Patients Receiving Gene Therapy

Cochlear implant patients exhibit improved speech perception in quiet environments after surgery, but their music perception and speech perception under noise are still unsatisfactory. Gene therapy is a novel and promising treatment for congenital hearing loss to recover natural hearing sensations. To date, for patients with congenital deafness, there has been no study on their ability to perceive and understand sounds, such as speech perception in noise, music and directional perception, after hearing recovery owing to gene therapy. In addition, the difference between the two treatments in those perceptual levels postoperatively remains unknown.

Therefore, the investigators designed a single-center cohort study. Based on the intervention method, congenital deafness patients are divided into two groups: the cochlear implant group and the gene therapy group. In the present study, a full-scale evaluation of the two groups will be conducted. The battery encompasses auditory speech perception, cognition, psychological status, and auditory cortex development. A comparative analysis will be conducted to examine multidimensional differences between the two groups, shedding light on the divergent outcomes of gene therapy and cochlear implants for patients with congenital deafness.

Inclusion criteria

• Patients with congenital hearing loss with hearing thresholds ≥65 dB receive either gene therapy (previously received gene therapy and standardized postoperative rehabilitation and follow-up or plan to receive gene therapy), or cochlear implant surgery. Healthy participants with bilateral hearing thresholds within the normal range (≤20 dB), generally matched to the gene therapy group and the cochlear implant group by age and sex.
• Age ≥ 6 months old, regardless of gender.
• Mandarin Chinese as the native language.
• Participants and their guardians must provide informed consent before the trial, voluntarily sign a written consent form, and commit to follow-up at specified time points.
• Capable of effective communication with researchers under the guardian's assistance and willing to cooperate and comply with the researchers' requirements.
• The participant's guardians should have a correct understanding of the trial and appropriate expectations regarding potential benefits.

Exclusion criteria

• Presence of other otological disorders that may interfere with the surgical outcome or interpretation of study endpoints, such as middle/inner ear dysplasia or malformations that affected the therapeutic effect revealed in CT/MRI scans within 3 months, vestibular-cochlear nerve abnormalities, acute/chronic otitis media, Meniere's disease, etc.
• Presence of other severe congenital diseases.
• Presence of severe systemic diseases or in the acute onset of diseases, such as pulmonary tuberculosis, active hepatitis B or C infection, active herpes zoster infection, pancreatitis, renal insufficiency, etc.
• Individuals with low immunity, a history of immune deficiency or organ transplantation.
• Individuals with a history of neurological or mental disorders, such as epilepsy or dementia.
• Patients with contraindications for surgery or anesthesia assessed by a surgeon, anesthetist, or designated personnel, such as cardiovascular or cerebrovascular events in the past 6 months, allergies to the planned medications, etc.
• Gene therapy group: gene therapy did not restore hearing; Cochlear implant group: presence of hereditary syndromic deafness or other conditions that seriously affect the efficacy evaluation.
• Any other conditions for which the investigators consider the subject unsuitable for participation in this clinical study.