New hope for hearing impaired babies thanks to Monash engineers

Research teams from Monash University Electrical and Computer Systems Engineering and Bionics Institute have used cutting edge light technology to non-invasively image brains to help diagnose hearing impairments in infants and prescribe the most effective treatment as early as possible.

Their work is of significance to those in the early childhood education and care (ECEC) profession, given the severe impacts of prolonged hearing loss on children’s ability to develop speech and language. Currently, several diagnostic tests are required to accurately determine the extent of hearing impairment in infants. Tests can extend for several months and are stressful for both the child and the parents.

The new test, which includes light technology which is invisible to the human eye, is the work of PhD student Ishara Paranawithana and a team of researchers who used functional near-infrared spectroscopy (fNIRS) to non-invasively image the brains of a group of normal hearing infants and measure how language areas of their brains develop and interconnect over time as they grow older. 

The study analysed the functional connectivity changes that occur in the brains of normal hearing infants to explore how primary language areas typically develop in the first year of life.

Mr Paranawithana said the objective measurements of connectivity from normal hearing infants can be used as potential biomarkers to compare against those of infants with hearing impairment to determine their level of language development.

“Since the age of the infants in our study varied considerably, we could quantify how these regions become increasingly functionally linked together with age and compare with the connectivity levels seen in adults by the end of the first year,” he said.

“By establishing the typical developmental trajectory of language areas in early childhood our results help us to better understand the altered connectivity and its effects on language delays often seen in hearing-impaired infants.”

fNIRS is not only child friendly, it is relatively inexpensive, and Mr Paranawithana believes that having diagnostic tools that facilitate early assessment of hearing helps infants with impaired hearing access effective treatments earlier in life, giving them the best chance to keep up with their peers.

These findings will contribute to future expanded capability of a new bionics device developed by the Bionics Institute called EarGenie, which is currently undergoing a clinical trial.

Professor Colette McKay, lead researcher of infant hearing at the Bionics Institute, said this study is critical to understanding how language processing develops in infants.

“The findings will help us track development of language in infants with hearing impairment, and optimise and fast track their early intervention,” Professor McKay said.

“Ultimately, we want to give babies born deaf or hard of hearing the best chance of hearing clearly and learning to talk.”

The results were published in the Journal of Neural Engineering and may be accessed here.