We often write about hearables and hearing aid technologies for adults. But what about infants? The U.S. and other countries with strong economies already test new newborn hearing, but that’s not the case in poorer countries largely because in-hospital hearing screening equipment is costly. Researchers at the University of Washington have developed newborn hearing screening with inexpensive earbuds and a smartphone app. A recent study published in Nature Biomedical Engineering reveals the results of testing with the low-cost device. Shyam Gollakota is the senior author of the study and a UW professor in the Paul G. Allen School of Computer Science & Engineering.

The research group tested 114 pediatric patients with the low-cost screening system. The group included 52 babies that were less than 60 months old. In addition they checked the device by testing 87 pediatric patients with previously identified hearing loss. The test requires a smartphone, cheap earbuds, and a microphone on a probe. Test technicians connected the earbuds to the microphone, With the earbuds playing two different tones in the child’s ear, the microphone detects and records a third tone caused by vibrating in-ear hair cells. The third tone has very low volume, so the UW students wrote a smartphone app with an algorithm that helps pick out the signal from background noise. The frequency of the third sound reveals the child’s hearing health.

The results of the study were impressive, with 100% sensitivity and 88.9% specificity. According to the study authors, the UW test equipment successfully detected all cases of hearing loss in the sample groups and were 88.9% accurate when they detected no hearing loss. The equipment isn’t designed to be the only hearing test, but to identify children who would then have further testing with conventional devices before getting treatment. It’s also notable that testing with the cheap test setup performance yielded results comparable to tests with commercial devices.

Next steps for the UW researchers start with developing the existing prototype further. The team is also working with the University of Nairobi and the Kenya Ministry of Health in a program to bring hearing screening to newborns and other children in that country.