Specialties · Otology
Cochlear implant: when it is indicated and how candidacy is assessed
A cochlear implant is an electronic device that stimulates the auditory nerve directly, bypassing the damaged part of the inner ear. It is considered in severe to profound hearing loss, in children and adults, when conventional hearing aids do not provide sufficient benefit. The indication comes from a team assessment.
Medically reviewed by Prof. Aline Bittencourt, MD, PhD, CRM-MA 7562 · RQE 1832 Updated on
What is a cochlear implant?
In typical hearing, the cochlea converts sound vibration into electrical impulses and sends them to the auditory nerve. When the cells in that structure are severely damaged, amplifying sound no longer solves the problem: there is no point sending a stronger signal to a system that cannot convert it.
A cochlear implant bypasses that step. It has two parts:
- An external part, the speech processor, worn behind the ear, which picks up sound from the environment and converts it into a digital code.
- An internal part, surgically implanted, with an electrode array positioned inside the cochlea, which stimulates the auditory nerve directly.
This is why it is not simply a more powerful hearing aid. It is a device that works on an entirely different principle.
Who is a candidate?
Candidacy is assessed in people with severe to profound sensorineural hearing loss who do not obtain sufficient benefit from properly fitted hearing aids. This includes:
- Children whose hearing loss was identified at newborn screening or during development.
- Adults with progressive hearing loss that has reached this degree.
- Adults with sudden hearing loss that has not recovered.
- In selected situations, single-sided deafness.
The degree of loss on testing is the starting point, not the conclusion. Two patients with similar audiograms may receive entirely different recommendations.
How is candidacy assessed?
| Step | What it answers |
|---|---|
| Audiometry and tympanometry | The degree and type of hearing loss |
| ABR | Hearing thresholds without requiring a voluntary response |
| Hearing aid trial | How much benefit amplification still provides |
| Speech-language assessment | The current state of language and speech perception |
| Imaging | Whether the cochlea and auditory nerve have favourable anatomy |
| Medical assessment | General health and fitness for the procedure |
No single element decides on its own. The indication emerges from the whole, discussed by a team that includes physician and speech-language pathologist, and talked through with the family.
What happens after surgery?
The implant is not switched on during the procedure. There is an interval for healing and, only then, activation: the moment the processor is turned on for the first time and electrode settings begin to be adjusted.
From there the longer work begins. The sound an implant delivers is unlike natural sound, and the brain has to learn to interpret it. This happens through:
- Mapping sessions, adjusting stimulation parameters over time.
- Auditory rehabilitation with a speech-language pathologist, which is part of the treatment rather than an optional add-on.
- Ongoing follow-up, with periodic reassessment.
Outcomes vary between individuals and depend on factors identified during assessment, such as the duration of auditory deprivation and previous experience with language.
The pathway at Clínica Rhinus
The case is handled from start to finish by the same team:
- Diagnostic work-up. Hearing tests are performed at the clinic, and imaging studies are requested and collated here.
- Candidacy assessment. The case is discussed alongside the speech-language assessment, and expectations are talked through with the patient and family.
- Surgery. Performed by Prof. Aline Bittencourt in a hospital setting.
- Activation and follow-up. Mapping, auditory rehabilitation and periodic reassessment, back at the clinic.
Prof. Aline Bittencourt completed a fellowship in advanced otologic and lateral skull base surgery and a PhD in otorhinolaryngology at the University of São Paulo (USP), and is an adjunct professor of otorhinolaryngology at the Federal University of Maranhão (UFMA).
The consultation and the surgery follow different rules. Consultations with Prof. Aline Bittencourt are self-pay: she does not see patients under health plans. The cochlear implant surgery, however, may be carried out under a health plan, including plans that Clínica Rhinus does not accept.
Sources: Brazilian Society of Otology · Brazilian Association of Otorhinolaryngology and Cervico-Facial Surgery (ABORL-CCF) · Flint PW, Francis HW, Haughey BH, et al. Cummings Otolaryngology: Head and Neck Surgery. 7th ed. Elsevier; 2020. · Tratado de Implante Coclear e Próteses Auditivas Implantáveis. 2nd ed. Thieme Revinter. · Bento RF, Bittencourt AG, Voegels RL. Seminários em Otorrinolaringologia. Fundação Otorrinolaringologia.
Frequently asked questions
Questions about otology
What is the difference between a cochlear implant and a hearing aid?
A hearing aid amplifies sound and depends on the cochlea still working well enough to make use of it. A cochlear implant does not amplify: it converts sound into electrical signals and delivers them directly to the auditory nerve, bypassing the damaged part of the inner ear. That is why it is considered when amplification is no longer enough.
Who is a candidate?
People with severe to profound sensorineural hearing loss, usually in both ears, who do not obtain sufficient benefit from properly fitted hearing aids. This applies to children and adults, and in selected situations to single-sided deafness. Candidacy is not determined by the degree of loss alone: it comes from the assessment as a whole.
Is there an age limit?
There is no strict age cut-off. In children, the earlier hearing loss is identified and intervention begins, the more use is made of the period when the brain organises language. In adults, what weighs most is how long the person has been without auditory stimulation and their previous experience with spoken language.
Will hearing return to how it was before?
Sound delivered by an implant differs from natural sound, and the brain has to learn to interpret it. Rehabilitation with a speech-language pathologist is therefore part of the treatment, not an optional extra. Outcomes vary between individuals and depend on factors assessed before the indication is made.
Are the consultation and the surgery covered by health plans?
They follow different rules. Consultations with Prof. Aline Bittencourt are self-pay: she does not see patients under health plans. The cochlear implant surgery, however, may be carried out under a health plan, including plans that Clínica Rhinus does not accept.
Does Clínica Rhinus carry out both the assessment and the surgery?
Yes. The clinic carries out the diagnostic work-up — audiometry, tympanometry, ABR and the imaging requests — and the candidacy assessment. Cochlear implant surgery is performed by Prof. Aline Bittencourt in a hospital setting, and pre- and post-operative follow-up takes place at the clinic.
Talk to our team about your case
Cochlear implant candidacy is assessed individually and involves several tests. Book a consultation and bring whatever already exists: audiometry, ABR, imaging, referrals. All of it is reviewed with you, in person.