“You’re putting a translating system into a biological system and expecting it to last many, many years and that is technically a very difficult thing to accomplish,” he said.
Explore this issue:February 2012
Dr. Jenkins said the FDA-approved Envoy Esteem has a great microphone system but involves an extensive operation involving removal of 3 mm of the incus to prevent feedback problems.
For patients with an Eustachian tube problem, he added, the microphone system becomes “fairly ineffective.” The implantable devices might have a place in helping certain patients, but not all patients need to go that far, he said.
“Remember, hearing aids are really quite good,” he said. “If the patients will use it, they’ll do well with it. The problem is… how many people actually use it.”
Unilateral vs. Bilateral Implants
David Haynes, MD, associate professor at the Vanderbilt Bill Wilkerson Center for Otolaryngology and Communication Sciences in Nashville, talked about the benefits of cochlear implantation. He said that since it is difficult to determine through tests which ear will perform better with the cochlear implant, the only way to be sure you’re implanting the ear best for the implant is to implant both ears.
That has to be balanced against the added risk, more difficult preparation, the time commitment, and increased incidence of vertigo, as well as “using up the ear before future technologies” emerge, Dr. Haynes said.
He pointed out that unilateral hearing loss is underappreciated, with 35 percent of children with hearing loss on one side failing one or more grades. There is now more of an inclination, therefore, to treat unilateral hearing loss, he said.
He pointed to a European analysis of a bone-anchored hearing aid (BAHA) database that found that 109 of 166 patients (66 percent) declined a BAHA after trying it pre-operatively (Eur Arch Otorhinolaryngol. 2011. [published online ahead of print August 11, 2011]).
The main reasons were not enough improvement in their hearing or tinnitus, both of which have been shown to improve with cochlear implants, Dr. Haynes said.
Auditory verbal therapy can be particularly fruitful for children getting cochlear implants, said Thomas Balkany, MD, director of the University of Miami Ear Institute. Auditory verbal therapists (AVT) generally have master’s degrees in audiology, speech pathology and deaf education and work with a mentor for three years, a period that includes 900 hours of therapy.
In AVT, parents are taught to teach their children to listen, with listening strategies integrated into daily routines. No sign language, total communication, or lip reading is involved. In studies comparing profoundly deaf children given AVT therapy compared to those using total communication, which involves using hand gestures and other means, the AVT group has fared significantly better on a slate of speech perception tests, Dr. Balkany said (Otolaryngol Head Neck Surg 1999;121:31-34).