According to the researchers at Monash University, Australia, prolonged hearing loss can severely affect how the brain’s language areas develop, affecting a child’s ability to develop speech and language. Currently, several diagnostic tests are required to determine the extent of hearing impairment in infants, which can take months and is often stressful for the child and their parents.
PhD student Ishara Paranawithana and his research team 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 as they grow older, specifically in the first year of life.
The researchers 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.
The results were published in the Journal of Neural Engineering, and can be read here.
In a statement, Paranawithana said: “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.
“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 a relatively inexpensive and child-friendly brain imaging technique suitable for clinical use. 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,” he added.
According to the research team, their findings will contribute to the future capability of EarGenie, a new bionics device developed by the Bionics Institute that is currently undergoing a clinical trial.
Professor Colette McKay, lead researcher of infant hearing at the Bionics Institute, said: “The findings will help us track development of language in infants with hearing impairment, and optimise and fast track their early intervention.
“Ultimately, we want to give babies born deaf or hard of hearing the best chance of hearing clearly and learning to talk.”