Earbud-like microphones might be usable for early detection of Alzheimer’s disease and other ailments, medical researchers say.
Rather than transmitting sound into the ear like conventional earbuds, these devices, which Miriam Boutros of École de Technologie Supérieure, in Montreal, calls “hearables,” transmit sounds out of the ear, after first blocking external sounds from coming in.
The effect is a bit like sticking your fingers in your ears to listen to your heart, or the singer’s trick of cupping a hand over their ear to better hear their own voice. By blocking out external sounds, the ear is better able to detect noises emanating from within the body.
Without technological assistance, this won’t give you detailed information (though it is excellent for keeping singers on pitch in a noisy room). But with sensitive microphones like those used by Boutros’s team, it’s possible to detect a lot more. Not just relatively loud things like heartbeat, breath, and voice, but even the blink of an eye, she said this week at a virtual meeting of the Acoustical Society of America.
It’s also possible to detect rapid eye movements called saccades—a fancy term for those quick flicks of your eyes when something catches your attention, or you are skimming a page of text. It works, she says, because as tiny as these motions are, they make the eardrum vibrate whenever we do them—vibrations that we can’t hear ourselves, but which can be picked up by the hearable’s microphone.
That’s important, she says, because an early sign of Alzheimer’s disease is saccades that are shorter, more variable, and less precise than normal. “Studying these patterns could be a critical step towards early detection,” she says. And, while there is no cure for Alzheimer’s, there are treatments that can slow its progress.
Next up, she says, is Parkinson’s disease, which she believes can also produce tiny changes detectable by the hearables.
For it, she says, her team’s research is focusing on noises produced by swallowing. “Parkinson’s disease patients have difficulty regulating their breath so they can swallow,” she says. “Swallowing is very visible when we get the signal from the ear microphone, so this could be a marker for Parkinson’s disease.”
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