October 31, 2022
Newborns throughout the United States examination to check for hearing loss. This test is important because it helps families better understand their child’s health, but it is often not available to children in other countries because the screening device is expensive.
A team led by researchers at the University of Washington has created a new hearing test system that uses a smartphone and inexpensive headphones instead. The team tested this device on 114 patients, including 52 infants under the age of 6 months. The researchers also tested the device on pediatric patients with known hearing loss. Their instrument performed as well as a commercial instrument, and it correctly identified all patients with hearing loss.
The team published these results Oct. 31 in Nature Biomedical Engineering.
“There are huge health inequalities in the world. I grew up in a country where there was no hearing screening, in part because the screening device itself is quite expensive,” said the senior author. Shyam Golakota, a UW professor in the Paul G. Allen School of Computer Science and Engineering. “The project here aims to use the ubiquity of mobile devices that people around the world already have—smartphones and $2 to $3 earbuds—to make newborn hearing screening accessible to everyone without compromising quality.”
Because babies can’t tell doctors if they can hear a certain sound, these tests rely on auditory mechanisms.
“When an external sound is played, the hair cells in the inner ear move and vibrate. The result is a very quiet sound that our instruments pick up,” said the co-author Dr. Randall Blyassociate professor of otolaryngology and head and neck surgery at the UW School of Medicine, who practices at Seattle Children’s Hospital. “This screening is very sensitive, meaning that if there is a concern about a patient’s hearing, they will be referred for a more thorough examination by a specialist.”
For the test, doctors send two different tones into the ear at the same time. Based on these tones, the hair cells in the ear vibrate and create a third tone, which doctors listen to.
One of the reasons that the commercial unit is expensive is that its speaker was designed to reproduce two tones without any interference. The UW researchers found that affordable in-ear headphones, in which each earpiece plays one of two tones, can be used instead. The headphones connect to a microphone in a probe that can be placed in the patient’s ear. The microphone records any sounds from the ear and sends them to the smartphone for processing.
“As you can imagine, these sounds coming out of the ear are very quiet and sometimes difficult to hear because of ambient noise or when the patient moves their head,” said lead author Justin Chan, a doctoral student at the UW Allen School. “We’ve developed algorithms on the phone that help us detect a signal even with all that background noise. These algorithms can run in real-time on any smartphone and do not require the latest smartphone models.”
The researchers tested their device at three hearing clinics in the Puget Sound area of Washington state. For each test, they tested four different frequencies, which is typical for these types of hearing tests. Participants ranged in age from a few weeks to 20 years.
The team is now working with colleagues to use the tool as part of a newborn hearing screening project in Kenya. The researchers teamed up with a team from the UW Global Health Division, the University of Nairobi and the Kenyan Ministry of Health to create the project “Toward Universal Newborn and Early Childhood Hearing Screening in Kenya,” or SET UP.
“Now this is a prototype that we have created. The next challenge is scaling up and then working with local experts in each country who are most familiar with the specific challenges in each situation,” Chan said. “We have the opportunity to really make a difference in global health, especially in newborn hearing. I I think it’s great to know that the research we’re doing can help directly solve real-world problems.”
Additional co-authors of this work Dr. Nada Aliresident in Otolaryngology – Head and Neck Surgery at the UW School of Medicine; Ali Najafiwho worked on this project as a UW postdoctoral fellow in the Department of Electrical and Computer Engineering; Anna Meehanclinical research coordinator at Seattle Children’s Center; Lisa Mankle, UW branch instructor of speech and hearing; and Dr. Emily Gallagher, assistant professor of pediatrics at the UW School of Medicine, who practices at Seattle Children’s. This research was funded by the National Institute on Deafness and Other Communication Disorders, the Washington Research Foundation, the Seattle Children’s Research Institute, the Seattle Center for Integrative Child Research, the Pilot Awards Support Fund Program, and Moore Inventor Award and the National Science Foundation.
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Grant numbers: T32DC000018, 10617
Tag(s): College of Engineering • Justin Chan • public health • Randall Bly • School of medicine • Shyam Golakota • UW Medicine