New hearing test to identify autism risk in kids: Study

A non-invasive and inexpensive hearing test may help identify infants with autism risk, say scientists who have found an inner ear deficiency in children with the disorder that may impact their ability to recognise speech. "This technique may provide clinicians a new window into the disorder and enable us to intervene earlier and help achieve optimal outcomes," said Anne Luebke from University of Rochester in the US.

"This study identifies a simple, safe, and non-invasive method to screen young children for hearing deficits that are associated with Autism," said Luebke. Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterised by impairments in social-communication skills and restricted and repetitive behaviours.

Researchers used a technique that measures what are called otoacoustic emissions. The test is akin to the screening that many newborns must undergo before leaving the hospital to check for hearing problems. Using miniature speaker/microphone earplugs, they were able to measure hearing deficiencies by listening for signs that the ear is having difficulty processing sounds. Specifically, the device's highly sensitive microphone can detect minute sound emission made by inner ear outer hair cells in response to certain tones or clicking sounds.

If these cells are not functioning properly, the device fails to detect an emission which indicates that inner ear - or cochlear - function is impaired. Researchers tested the hearing of children between the ages of 6 and 17, roughly half of whom have been diagnosed with ASD. They found that the children with ASD had hearing difficultly in a specific frequency (one-two Kilohertz) that is important for processing speech.

They also found a correlation between the degree of cochlear impairment and the severity of ASD symptoms. "Auditory impairment has long been associated with developmental delay and other problems, such as language deficits," said Loisa Bennetto from University of Rochester.

"While there is no association between hearing problems and autism, difficulty in processing speech may contribute to some of the core symptoms of the disease," said Bennetto. The findings can inform the development of approaches to correct auditory impairment with hearing aids or other devices that can improve the range of sounds the ear can process, researchers said.

Because the test is non-invasive, inexpensive and does not require the subject to respond verbally, this technique could be adapted to screen infants, an approach that the team is currently exploring, they said.
The findings were published in the journal Autism Research.