BLIND people may be able to 鈥渟ee鈥� with their ears if a British research
project goes as planned. Phil Picton, a reader in engineering control systems at
Nene College in Northampton, is embarking on a three-year project to build an
optophone鈥攁n appliance that turns light into sound to help blind or
partially-sighted people.
Picton is building on the work of a former student, Adrian O鈥橦ea, who died
before he could finish the project.
In O鈥橦ea鈥檚 system, the image is digitised by a computer and each pixel
allocated a sine wave of a particular frequency, with the rows of pixels at the
top of the image given high frequencies and those at the bottom low frequencies.
The amplitude of the wave assigned to each pixel is proportional to its
brightness. Finally, the set of sine waves in each column of pixels is combined
to produce a single sound.
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Picton says the computer will not try to pick out objects, but users will
gradually learn to recognise what is around them by the sounds produced in
particular situations. 鈥淭he computer will not try and interpret anything. A
person will be the intelligent part of the system,鈥� he says.
While the sounds will initially be unintelligible, Picton believes that after
training, blind people may be able to use the optophone to navigate.
John Gill of the Royal National Institute for the Blind in London remains
sceptical, however. 鈥淭he main problem with most of these devices is that they
have been developed by engineers with insufficient understanding of the
psychological processes needed by the blind user to interpret the information,鈥�
he says. 鈥淚n some cases, there are one or two users who become competent in the
use of the device, but the majority find the level of mental concentration
required is too much.鈥�
