When Hearing Aids Are Not Cutting It, Active Middle Ear Implants Might Do.
by Ashley Derrington, on December 4, 2018
You may not know they exist or what they are, but active middle ear implants – or AMEIs as they are sometimes referred to – have created new treatment options for some people with hearing loss. An AMEI refers to a surgically implanted hearing device that directly interacts with a part of the middle ear – one or more of the tiny middle ear bones (i.e., middle ear ossicles) – and is “active” in that it is imparting its own energy on the middle ear rather than just being a passive prosthetic. Active middle ear implants (AMEIs) can be either fully implanted with nothing external or semi-implanted with an external portion and an internal portion.
Some argue that part of the clinical value AMEIs offer is derived from “provid[ing] direct drive hearing in which sound is converted directly to vibratory energy and transmitted to the ossicles. …Converting sound directly to energy is more efficient and ultimately may provide improved speech discrimination and preferred sound quality compared to [conventional hearing aids].” [i]
How do they work?
Active middle ear implants work differently depending on the device, but they all directly drive the middle ear with mechanical energy as opposed to just making sounds louder, like the conventional hearing aids. The direct interaction with the middle ear can help overcome some of the limitations of conventional hearing aids.
Who’s a candidate?
AMEI’s are designed to alleviate a certain type and level of hearing loss.
The “type” of hearing loss is usually sensorienural hearing loss – the most common form of hearing loss -- and the “level” is typically between moderate to severe with unaided word recognition scores at or above 40% correct. Each AMEI, like any FDA-approved hearing device, has its own set of indications and contraindications.
For some people, AMEIs may offer an effective alternative to conventional hearing aids, but others are able to use AMEIs when hearing aids simply do not work for them for any number of reasons. For example, a person can use a fully implanted AMEI when they cannot tolerate external hearing aids or cannot effectively wear external hearing aids in their career. Some other reasons for not being able to wear a hearing aid may include ear-mold allergies, skin problems in the ears, outer ear infections, narrow, collapsed or closed ear canals, malformed ears, and more.
What to expect from an active middle ear implant
It is important to understand that no hearing solution is a cure for damaged hearing – you cannot undo or reverse the hearing loss you already have (at least not yet!). You will not have super human hearing, and you will not be able to hear as you were before hearing loss became part of your identity.
As with other treatment options for hearing loss, not everyone does better on their post-implant hearing tests than they did on their pre-implant hearing tests with their hearing aids. Some do better, a small fraction does worse, and many do about the same. But typically, people picking an AMEI after trying hearing aids for years are doing it for a reason that cannot always be captured in a hearing test. There are many other important factors, and you’ll need to weigh all of your options before making a decision.
Your audiologist and surgeon will look at your hearing tests and observe how you do with conventional hearing aids. They will help you understand what to expect and discuss potential risks of the surgery, potential side effects and whether further surgery may be needed. With reasonable expectations and a good understanding of the specific AMEI you are exploring you will get more out of the AMEI you choose.
Below are some of the benefits various AMEI’s might offer:
- Some do not have anything external or in the ear, so you are completely free of any of the drawbacks of external devices.
- No acoustic feedback.
- No or less occlusion.
- Reportedly more “natural sound” than conventional hearing aids
- Help in managing everyday situations more easily
- Fully implanted devices offer increased safety because they are worn all day, everyday in nearly any situation. For example, you don’t have to worry about a fully implanted device getting wet so you can wear it around water. You will hear an alarm at night or a baby calling from the other room.
- Fully implanted devices offer benefits around water and active lifestyles and remove discomfort of wearing something in the ear canal.
- Most devices are not approved for any use in MRI environments. The Esteem is the only AMEI that has received FDA’s MRI-Conditional approval for 1.5 and 3.0 tesla. If the ability to get an MRI is important to you, consider your options closely with your doctor.
References:
US National Library of Medicine National Institutes of Health
[i] Shohet, J. A., Gende, D. M. and Tanita, C. S. (2018), Totally implantable active middle ear implant: Hearing and safety results in a large series. The Laryngoscope. . doi:10.1002/lary.27246
