Hugh Hetherington Hearing Aid Museum
Hugh Hetherington Hearing Aid Museum

The Hearing Aid Museum

Hearing Aids of all types—Ear Trumpets, Carbon Hearing Aids, Vacuum Tube Hearing Aids, Transistor Hearing Aids, Body Hearing Aids, Eyeglass Hearing Aids and much more!

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Click on the "General Information" button (top button above) for an overview and general information on this category of hearing aid.


Body Type Transistor Hearing Aids

Siemens Model 331 "Phonophor Adaptomatic" Transistor (Body) Hearing Aid

The Siemens Model 331 (Phonophor Adaptomatic) Transistor Hearing Aid was manufactured by Siemens A.G. of Germany in 1957. It was a 3-transistor model.

It measured 2" x 1⅜" x ⅝" thick.

The volume control is on the right side near the top. On the top is a 2-position slider switch (probably the on-off switch).

On the left side towards the back from the battery door is a 3-position slider switch (probably a high, medium, low tone switch).

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The Siemens Model 331 showing the battery compartment. It used a 625 mercury battery. Note that the plug for the earpiece holds the battery door shut when it is plugged in.

The button on the lower left side is the slider switch that likely switches between the microphone and the t-coil.



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