July 29, 2013

Hearing Aids and 3-D Printers

Parker,-Molly-NEWBy Dr. Molly Parker
Parker Audiology, PC

Creating new hearing aids has become very high tech!!

With the invention of 3-Dimensional Printers, the hand-made aspect of hearing aids has gone by the wayside. While some people may feel saddened that the artisan aspect of making hearing aids is no more, I want to comment on how 3-Dimensional printers have truly revolutionized the way hearing aids and earmolds are made. Hearing aids are still as customized as before, but they are now faster, safer, better made, and more convenient for everyone.

In the past, we used to obtain earmold impressions and mail them in. Sometimes they melted a little bit in the hot mailbox in the summertime. The manufacturer would create a negative cast and create the proper plastic shell formed to your ear. Once this plastic cast was made, the material was poured out to create the hollow shell on the inside. If the timing was too fast, the shell was too thin and it would crack. If the shell was too thick, there was not enough room for the battery, microphone, etc. The circuit and shell were glued together, everything was filed, polished (which often took hours) and sent back to me. The entire process was hand-made and usually took about two weeks to get back to me. Many chemicals, fine dust, and good eyes and hands were involved, as well as grinding stones, potential injury to fingers, etc. This process was still used as recently as 10 years ago.

Today, we are able to obtain silicone earmold impressions, which have a more durable life in the hot mailbox. These
are scanned digitally with thousands of reference points in a 3-dimensional picture. The earmold is “created” from the ear canal by a technician working with a special computer program. They can see your specific ear canal with your specific hearing aid’s fit inside the 3-dimensional picture. In this picture, they can move the battery door, microphone, receiver, etc. to make sure it is in the best place for you to hear. The hearing aid is actually built layer by layer in a 3-dimensional printer. If you look at the printer, it appears like an aquarium with sand on the bottom. The entire process usually takes about three to four days.

This benefits our patients, because if you needed something changed, we can call and discuss the physical fit with a specialist at the factory and explain (so we can both see the picture) how a particular area needs to be changed. If a patient loses their earmold or hearing aid, a simple phone call prompts the company to remake the shell without making the patient come in for a new impression. This saves time, money and effort for everyone.