How do you build a better hearing aid? Researchers at MIT believe the answer is to bring new eyes to the ears, with imaging technology to make an aid that fits the user perfectly. At present, custom hearing aids are modeled on molds made by injecting silicone into the ear. Douglas Hart, the principal investigator behind a new 3-D digital ear-canal scanner, says there are a number of problems with this antiquated method. First, it’s uncomfortable. Second, it can’t measure shifts in ear-canal shape when the body moves — for instance, when patients open their mouths. And third, it doesn’t gauge the pliability of the soft tissue, which varies from person to person and can radically affect fit. With the new device, however, Hart says, “we can actually film the 3-D shape of an ear as you chew.”
The scanner is essentially a fiber- optic camera inside a liquid-filled mem-brane. Once inserted into a patient’s ear, the membrane expands to fill the canal and creates a 3-D image by gauging light. The technician then measures soft- tissue compliance by changing pressure in the membrane, which should help hearing-aid makers craft devices that better seal the ear canal.
The invention is being commercialized with the help of MIT’s i-Teams program, which pairs Sloan School of Management experts with technical brainiacs. With a planned pay-per-scan revenue model and a target rollout date of 2011, the team could profit handsomely from the aging pop-ulace, including the device’s creators themselves. “Inevitably,” Hart says, “it’s something I’ll probably end up using for myself.”