Sonotone Model 988 Vacuum Tube Hearing Aid
The Sonotone 988 was reputed to be the slimmest and
lightest vacuum tube aid ever manufactured. It weighed just over 3 oz.
It measured 3.0" high x 1¾" wide by ⅝" thick.
The Sonotone Model 988 was manufactured by Sonotone International,
Inc. in 1952. As it happened, this was only months before the first
transistorized hearing aids came out and made vacuum tube hearing aids
obsolete.
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The Sonotone 988 shown with its back taken off. It used a No. 401 mercury cell for the A battery
(left),
and a No. 504 15 volt battery for the B battery.
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The inside of the Sonotone 988 showing the front of the circuit board
and the tiny tubes it used.
Incidentally, Sonotone made their own tiny vacuum tubes and miniature components.
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The inside of the Sonotone 988 showing the back of the circuit board. |
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The Sonotone 988 in its original box.
If you are interested,
read
the news item on the Sonotone 988 that was printed in the New York Times
on December 12, 1952.
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