How blind baby 'sees’ through its ears

Press, 15 September 1976, Page 21

How blind baby 'sees’ through its ears

By

DAVID DUGAN,

of the

“Sunday Times,” London

A device nas been developed that enables babies bom blind to perceive the world through echoes from an ultrasonic scanner. Dr Tom Bower, of the Edinburgh University psychology department, told the British Association annual conference that he gave the device to a 16-week-oid boy in the United States and the child responded to it within half a minute of putting it on. The battery-operated scanner sends out a pulse of ultrasound through a cone attached to the forehead. Through earplugs, the baby is able to hear echoes in stereo which tell him what lies in front. By moving his head he can detect sounds from different parts of the room. The closer the object is, the lower the pitch of the sound. The bigger it is, the louder the sound. The child can also establish whether the object is hard or soft: a hard object will give a clear sound and a soft one will give a fuzzy sound with overtones. Normal voice commands can be heard by the baby while he is wearing the device.

Although the device has

a British patent, it is not yet available in Britain. It was developed in Oakland, California, by Professor Harry Kaye, and was modified for Bower’s use by Matt Mahgoun, an engineer working for an American company called Telesensory Systems. Dr Bower first tried it out on a blind baby from the Berkeley children’s hospital in California. The baby, Denis Daughters, seemed delighted, and played hide-and-seek with his mother after a few days. He enjoyed finding her in a room. At the age of nine months, he had reached the development stage of a normal sighted baby. He was able to perform tests such as balancing an object on two prongs or on a table edge This ma sound trivial, but few normal sighted children can perform such a task before this age. Dr Bower had envisaged a complex training programme to teach children to use the device, but Denis didn’t need much training. He was able to “see” his giant rubber caterpillar, to know its sounds, and become attached to it. ' An ex-

penmenter tried to find out if Denis couid detect a tiny object; after several unsuccessful attempts to grab it, Denis managed to knock it out of the experimenter's hand. There were some problems. After a while, the headgear and earplugs hurt the baby, so he tried to take it off. Dr Bower thinks it might be a good idea to have a switch which could be turned off by the child, just like closing the eyes. Experiments are continuing at Edinburgh.

Experiments with the device and its senes of pips and squeaks have enabled Dr Bower to reach conclusions about mans evolution. For example, eyes and ears have evolved over millions of years but, as Dr Bower says: “No organism in evolution was ever given this sort of information to make sense of.

“There are two possible conclusions: firstly, that man has evolved to such an extent that anything can be rapidly learned; or secondly, that immature perception doesn’t respond to immediate sensory information such as light, sound and touch, but re-

sponds to changes detected.” Thus Dr Bower believes that a young child does not know whether he is hearing or seeing something. He says that when an object approaches the eye of a sighted child, he sees it as an expanding pattern. For Denis, who hears a change in pitch, the sequence is the came. For him, there is in theory “no difference from seing with the eyes, except, of course, there is no colour,” says Dr Bower. As sighted babies become older, they rely more and more on vision. What tends to happen with blind babies is that they are eager to reach out towards sounds and touch objects for rhe first 20 week.-, but after that they begin to lose interest. The blind child will not usually begin to recover from "this passive state until he is about 17 months old. That is why Denis is to lucky. He has been able to bridge this period of sensory deprivation and take an active part simply by turning his head and picking up echoes from new objects.