- Dr. Michael Disher
When to Implant? Considerations for Adult Cochlear Implants
Updated: Jun 16, 2021
For those struggling with hearing loss, the fear of the unknown is often more powerful than the motivation to take back what’s been lost. But expanding indications and candidacy criteria for cochlear implantation reinforce why it is critical to consider or recommend a surgical option sooner, rather than later. Evidence demonstrates that better hearing performance outcomes following cochlear implantation are correlated to a patient’s duration of hearing loss and residual low frequency hearing. 1 In other words, the earlier an individual is evaluated, identified, and recommended for surgery, the better positioned they are to maximize the hearing performance benefits of implantation. Don’t Wait - Duration of hearing loss A large body of evidence has indicated that shorter duration and preoperative word recognition scores are indicators of better post-operative scores. Both Derinsu et al and Plant et al studied these factors and found that the relationship between hearing loss duration, pre-CI word recognition scores and/or residual hearing were predictive of better outcomes. 1,2 Don’t Wait – Residual hearing Benefits of bimodal hearing are boosted when low frequency hearing in the implanted ear combines with the cochlear implant and partners with acoustic hearing in the contralateral ear. 3 The more hearing a patient has, the more opportunity there is to leverage it. Implant recipients using acoustic stimulation in the implanted ear with residual hearing have been shown to achieve: 2.9 dB signal-to-noise ratio improvement relative to the bimodal condition 4 and improved localization ability with use of low frequency cues. 5 Bimodal hearing, with a cochlear implant on one side and hearing aid on the other, provides its own benefits. The acoustic stimulation can improve sound localization, hearing in background noise and music appreciation, all which contribute to hearing performance and quality of life.
When presented with the evidence demonstrating the correlation between duration of hearing loss and performance outcomes, the message is clear – Don’t Wait! As a rule of thumb, if an individual’s hearing thresholds exceed 70 dB PTA (.5, 1 and 2 kHz) and/or their aided speech scores are at or below 50%, refer them for a cochlear implant evaluation.