What Are Audiological Assessments for Cochlear Implants?
Audiological assessments are specialized tests to determine if someone qualifies for a cochlear implant. These tests evaluate the type and severity of hearing loss, the effectiveness of hearing aids, and the health of the auditory nerve.
Key Tests for Cochlear Implant Candidacy
1. Pure-Tone Audiometry
- Purpose: Measures the quietest sounds a person can hear across different pitches (frequencies).
- Process: Wear headphones and respond to beeps.
- Result: Severe/profound hearing loss (thresholds ≥70–90 dB) usually qualifies.
2. Speech Recognition Testing
- Purpose: Checks how well a person understands speech with hearing aids.
- Process: Listen to and repeat words/sentences in quiet and noisy settings.
- Result: ≤50% accuracy with hearing aids indicates candidacy.
3. Otoacoustic Emissions (OAE)
- Purpose: Tests inner ear (cochlear hair cell) function.
- Process: A probe in the ear measures echoes from healthy hair cells.
- Result: No emissions suggest sensorineural hearing loss.
4. Auditory Brainstem Response (ABR)
- Purpose: Evaluates the hearing nerve’s response to sound.
- Process: Sensors on the head record nerve activity during sound exposure.
- Result: Weak/no response confirms nerve involvement.
5. Imaging Scans (MRI/CT)
- Purpose: Checks cochlea structure and nerve integrity.
- Why?: Ensures the cochlea can accommodate the implant’s electrode array.
Who Needs These Tests?
- Adults/children with severe-profound hearing loss.
- Hearing aid users with poor speech understanding.
- Infants who fail newborn hearing screenings.
Why Are These Tests Important?
- Confirm if hearing aids are insufficient.
- Rule out issues like auditory neuropathy.
- Ensure the cochlea and nerve can support an implant.
