Health

Locating objects using echoes 'needs two good ears'

An ear Image copyright Science Photo Library
Image caption Good hearing in both ears is needed to locate objects using echoes, as bats and dolphins do

Locating objects by listening to echoes is an important skill for both blind and sighted people, says University of Southampton research.

It is similar to a technique used by bats and dolphins, which requires good hearing in both ears.

In experiments, scientists found that people who lost hearing in one ear struggled in tests on locating objects.

As people age and their hearing declines, audiologists should be aware of this fact, the study said.

The study, published in Hearing Research, conducted a series of experiments with both blind and sighted people, asking them if objects were to the left or right of them.

Sounds were manipulated in various ways in a 'virtual auditory space' to give the impression of objects being in various different positions in the space.

The study found that people could locate the object accurately, but only if they had good high-frequency hearing and in both ears.

'Struggle'

Dr Daniel Rowan, lead author of the study and lecturer in audiology at the University of Southampton, said this could affect elderly people suffering from hearing loss, because they tend to lose hearing at high frequencies in both ears.

"We wanted to get some insight into how much those particular forms of hearing loss might affect users of echoes to locate objects: our results suggest they would struggle."

Dr Rowan said hearing aid services tend to focus on how well someone can hear speech.

"Our research indicates that those services also need to take into account whether someone needs to hear echoes in their daily life," Dr Rowan said.

"For example, they might need hearing aids in both ears, despite the emerging trend in some parts of the country to only fit one."

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