Study finds early vision loss makes judging sounds difficult

People who lost sight early in life are less accurate at estimating distances, study

People who experience partial vision loss in early childhood find it more difficult to accurately judge the location of sounds than those who lose their sight later in life, according to new research.

The study, led by Anglia Ruskin University (ARU) in collaboration with the University of East Anglia (UEA), was published in the journal Optometry and Vision Sciences. It is the first to compare how people with early (before the age of 10) and later onset vision loss judge the distance of sound.

The research involved 52 participants under 33 years old. Each took part in 480 trials, estimating the distance of sounds emitted from 1.2m to 13.8m away. The sounds varied between speech, music, and noise.

Differences in estimations between those with early and late onset vision loss, as well as a fully-sighted control group, were greater for closer distances. People with early-onset vision loss judged that sounds from close distances, up to five metres, were coming from further away.

Distance judgements were not significantly different between the control group and those with late-onset vision loss.

Lead author Professor Shahina Pardhan, Director of the Vision and Eye Research Institute at ARU, said: “These results suggest that people who suffer vision loss at birth or in early childhood are more likely to struggle to accurately judge the distance of close-range sounds.”

“This is the first study of its kind and is important when assessing the healthcare needs of people who suffered partial vision loss early in life, such as at birth or in childhood, who tend to be reliant on their other sensory abilities,” Pardhan added. “Clearly a difficulty in judging short and medium distance sounds could have safety implications, for example when attempting to cross the road.”

The study was co-authored by academics from the University of Cambridge and Sankara Nethralaya Eye Hospital in Chennai, India.

Co-author Dr. Andrew Kolarik, of UEA’s School of Psychology and ARU’s Vision and Eye Research Institute, said: “Many studies have shown that fully blind people display measurable changes in their hearing abilities, showing either better or worse performance compared to sighted people depending on the hearing task they are given.”

“This study shows that even partial vision losses can lead to changes in hearing abilities, especially if vision is lost early on in life,” Kolarik concluded.