In-the-ear hearing aids (small hearing devices that sit inside the ear canal and do not wrap around the ear – also known as behind-the-ear or BTE hearing aids) are generally preferred by first time users. While ITEs have similar sound quality and performance to BTEs, they also have some challenges; they are not always as small as people would like, due to the natural properties of the standard shell material (acrylic) they can break, and they are not always comfortable.
Phonak has been working to identify a solution to these issues, and a new shell material, titanium (yes, the metal) has been discovered as the answer.
But how can a titanium hearing aid solve the most problematic and longest running issues related to in-the-ear devices?
For many people, the biggest barrier to getting hearing aids is the worry that they will be visible. On average, it takes an adult 10 or more years from the time they are diagnosed with a hearing loss until the time they decide to get help, according to a study published in the Health and Technology Assessment journal. The majority of adults also say that their first priority in a hearing aid is that it is invisible. In order for a device to be invisible in the ear canal, it needs to be as small as possible. Acrylic shells have requirements to be a specific minimal thickness in order to be sturdy enough for daily wear, and this restriction has limited how small hearing aids could be made in the past.
In-the-ear hearing aids can be a more discreet solution than BTE hearing aids, and now titanium custom shells have allowed them to be smaller than before.
Titanium is a non-corrosive metal that is both strong and dense. It is this strength that allows the metal to remain stable and viable even when it is very thin- only 0.2 mm, or about the width of a piece of paper. Thin titanium hearing aid shells create 30% more additional space inside the device, which can be leveraged when customizing the hearing aid to the individual ear to make it as small and invisible as possible.
The discreetness offered by a titanium custom shell could help eliminate the fear that someone will see their hearing aid. By overcoming this barrier, it may enable the individual to seek help and acquire a hearing aid for the first time.
Traditional acrylic custom hearing aid shells have the tendency to be more fragile than BTE housing, which is made from a different material. Secondly, the most discreet acrylic hearing aids that sit deep down inside the ear canal make shell wall thickness compromises in order to attain that small size. When acrylic is at its thinnest, sometimes it can break. We are all human and sometimes a hearing aid will fall on the floor, get stepped on, or break apart under the pressures of daily wear and tear.
Titanium is 15x stronger than acrylic. The material is so strong that it has been used in other industries for years, including dental and medical implants, airplane and ship exterior housing, luxury watches and sports equipment, such as bikes, golf clubs, and climbing pitons. If it’s tough enough to be on the outside of an airplane, its strong enough to stand up to the rigors of daily wear.
For some people, once they overcome the hurdle to get help and purchase hearing aids, over time they end up in the drawer because they are not comfortable enough to wear. Hearing aid discomfort can mean two different things; physical comfort (how it feels inside the ear) and acoustic comfort (how natural their own vocal quality sounds). When a patient refers to unnatural sound quality in their own voice, this is called “Occlusion.” Some describe occlusion by saying they feel “stopped up” or that their own voice is “boomy” or “hollow”. In many cases, people who are not able to overcome occlusion eventually stop wearing their hearing aids consistently.
To address physical comfort, hearing aid shells need to fit properly. Each individual’s ear canal has unique anatomy, like a fingerprint. For some, modular hearing aid ear pieces can cause discomfort and itching, and occasionally pain. Titanium shells are custom built for each user to take into account all of their anatomical characteristics. Your health care provider will take an impression (a 3D cast) of your ears at your appointment. The hearing aids are then tailor-made to fit you like a glove. Titanium 3D printers are more precise and have lower tolerances than the standard acrylic printers and can result in a better fitting device. When your hearing aids fit properly, they are physically comfortable day in and day out.
Occlusion and acoustical comfort are addressed with venting. A vent is a hollow tube that runs through the entire hearing aid. When this vent is an adequate size, enough air can get through creating a less plugged feeling, and better more natural vocal quality. Due to the strength of titanium custom shells, they can be printed at HALF the thickness of acrylic. The walls of the shell reduce from 0.4mm to 0.2 mm. With 0.2mm thinner walls, that added space can be used to make a bigger vent, and will result in less occlusion. When a patient feels physically and acoustically comfortable in their hearing aids, they are much more likely to be a successful and consistent user.
To learn more about Phonak’s Virto B-Titanium hearing aids, visit your health care professional or audiologist. If you don’t have a health care professional, you can location one here one, here.