3D Printing

The world of 3D printing is growing at a rapid pace. From highly technical applications in medicine, industry, and architecture to hobby uses at home, this field is going gangbusters. No matter the use, essentially 3D printing is an additive manufacturing process that creates a physical object from a digital design.

These days you can get a home-use 3D printer in Michael’s Craft stores. But my introduction was back in the early 2000’s when I visited the production lab at Widex hearing aids to see their new process being used to create custom hearing aid shells. It was mouth-dropping amazing to watch. Layer upon layer of light-curing acrylic resin appears to be built up from nothing to form the new hearing aid shell. Since Widex introduced the technology in 2003, almost all hearing aids are now using 3D printing, to the great benefit of hearing aid wearers.

Creating a optimally fitting hearing aid is all about the specific needs of every individual. Each ear canal is different. This is not an automated process; it allows the designer to create a model for each ear, placing the components individually in each unique shell.

Therefore, the hearing aid shells fit precisely from the start. They can be smaller and more discreet, with better comfort. A better fit ensures more amplification and less risk of feedback. The impression of the user’s ear only needs to be taken once because the scan is kept on file, and can be replicated or modified as needed. A smoother finish and higher shell quality is produced, resulting in a nice improvement for the hearing aid wearer.

After all, if a hearing is is a tiny bit too big, you may feel it as pressure, and if a tiny bit too loose it may allow leakage of sound and result in acoustic feedback. Precision allows the fit to be perfect.

Here is a peak into behind-the-scene process:

The hearing care professional makes an accurate silicone impression of the ear.

This is scanned into a computer program.

The information is converted into a three-dimensional image.

An earmold or hearing aid shell is then modelled so it fits precisely in the ear canal.

This data is transferred to the manufacturing unit.

A powerful laser is used to build the shell or earmold layer by layer. Each layer is only 0.1mm thick.
Starkey Manager of Mechanical Engineering Brian Dobson recently said that 3D printing is changing the world of manufacturing and product development. He says there is an almost-exponential growth in patents related to 3D printing, and this product area is now poised to be a $23 billion industry by 2020. It certainly is bringing the best ever custom hearing aid fits to our patients, and that is the part of this story that we care most about!