In-Ear Microphones Studied for Early Signs of Alzheimer's Disease

Researchers are investigating whether microphones placed inside the ear can pick up signals associated with eye movements, which might one day support monitoring for signs of neurodegenerative disease. This is an exploratory approach, not an established test for Alzheimer's disease.

Alzheimer's is a progressive condition that can affect memory, cognition and movement. The article says it affects more than 50 million people worldwide, but does not specify the source or denominator for that figure. Gradual progression can make early diagnosis difficult.

Research presented at an acoustics meeting

Miriam Boutros of École de Technologie Supérieure and Dartmouth collaborators planned to present the work at the Acoustical Society of America's 187th virtual meeting, November 18–22, 2024. The project was co-led by Rachel Bouserhal at École de Technologie Supérieure's Research Laboratory on Hearing and Assistive Devices and Chris Niemczak of Dartmouth's Geisel School of Medicine.

People with Alzheimer's can experience changes in rapid eye movements, or saccades, which may become slower, less accurate or delayed compared with healthy controls. Researcher Arian Shamei said the speed and precision of eye movements draw on both motor skill and cognitive function. Conventional eye tracking requires specialized equipment.

Listening for eye movement

Boutros described a “hearable” headset with an in-ear microphone that records physiological signals from inside the body. Eye movements can create eardrum vibrations detectable by sensitive microphones. The team is testing volunteers with both a hearable device and a conventional eye tracker to identify signals corresponding to saccades and explore whether patterns differ in neurodegenerative disease.

The long-term goal is noninvasive, continuous monitoring for Alzheimer's and perhaps other conditions. Shamei said the team hopes eventually to distinguish diseases by symptoms reflected in in-ear signals. The reported work does not show that a consumer headset can currently diagnose or screen for Alzheimer's disease.

Original report: Acoustical Society of America.