A new system has been presented for the conversion of images into
sound patterns. The hardware implementation employs a special pipelined
architecture for the real-time digital calculation of sound samples.
The design aimed at obtaining a portable, low-power and low-cost system.
To this purpose, the prototype system was constructed entirely out of
standard, commercially available components. The technical feasibility of
the approach has been proven by the construction of a fully functional
system, which, by means of inverse mappings, was shown to preserve
image information up to a resolution corresponding to estimates for
achievable resolution. Some practical parameter restrictions
were derived from known limitations of the human hearing system.
The resolution provided by the system itself appears sufficiently
high to deal with many practical situations normally requiring human
vision, as the system was designed towards possible later use by the
visually impaired.
However, the further development towards a practical
application of the system still awaits a thorough evaluation,
with blind persons. This is needed to determine and quantify
the limits of attainable image perception, before any firm
conclusions about the usefulness of the system can be drawn,
because only the technical feasibility has now been established.
Such an evaluation should involve both (young) children and adults,
while distinguishing the congenitally blind from the late-blinded,
because neural adaptability may drop rapidly with age, and the
neural development may strongly depend on prior visual experiences.