Hybrid/EAS (Electrical Acoustic Stimulation) Implant is combination of acoustic hearing (via hearing aid) for low frequency and electric hearing (via cochlear implant) for mid-high frequency treated for partial deafness patient in the same ear.
Hybrid Implants enables to hear more naturally in all frequencies compared with conventional CI.
<Fig> Patients with steeply sloping audiograms whose hearing impairment was characterized by normal or slightly elevated thresholds in the low-frequency band, with nearly total deafness in the higher frequencies. Amplification from hearing aid is limited, so it doesn’t help hearing especially in speech discrimination.
HYBRID implants or EAS system is an innovation technology for this partial deafness. Sound processor and thinner, tapered, flex straight electrode array with soft tip electrode were developed to preserve remnant hearing cells.
Candidate for the treatment with Hybrid Implants
1. Partial deafness (PD)
Stable mild to moderate hearing loss in the low frequencies (up to 500 Hz) and severe to profound hearing loss in the mid and/or high frequencies (above 1500 Hz).
2. Speech scores
The patient’s monosyllable score should be ≤ 60% (65dB SPL) in the best aided condition
- When tested with conventional hearing aids, candidates usually present with limited benefit for speech (in quiet and noisy surroundings).
- Example of limited benefit=score of 10% to 60% in ear to be implanted on monosyllabic word test (aided).
3. Biographical Details of Hybrid Implants
No rapid progressive hearing loss
No malformations or obstruction of the cochlea
We have demonstrated that these patients achieved substantial improvement in speech discrimination and communication skills using cochlear implant in the same ear with natural hearing with/without amplification.
Clinical studies demonstrate significant improvement with Hybrid/EAS over acoustic amplification alone, which is particularly beneficial for improving sound quality and understanding speech in noisy environments.