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.

 

Vacuum Tube Hearing Aids: 1921-1953

Sonotone Model 977 Vacuum Tube Hearing Aid

The Sonotone Model 977 vacuum tube hearing aid was manufactured by Sonotone International, Inc. of  Elmsford, NY in 1951.

The Sonotone Model 977 vacuum tube hearing aid weighed 4.9 oz. (140 g) without the batteries. It measured 3 7/16" high x 2⅛" wide by ⅞" thick (8.8 x 5.4 x 2.2 cm). It used 3 vacuum tubes.

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Front view of the Sonotone Model 977 vacuum tube hearing aid. The silver-colored metal case had a grey/blue plastic insert (center). Note the Sonotone "S" at the top of the gold-colored pocket clip (top center).
 

 

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Top view of the Sonotone Model 977 vacuum tube hearing aid showing the 3-position on-off switch (left), volume control (center) and the receiver cord jack with the receiver cord plugged into it (right).

The 3-position on-off switch was something that Sonotone used. There was the "full on" position (shown) (2nd click) and the "bi-focal" position (1st click). In this position it "dimmed out"  background sounds for clearer hearing in crowded, noisy places".

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Close-up view of the top right corner of the Sonotone Model 977 vacuum tube hearing aid  showing the recessed two-pronged receiver cord jack and receiver cord plug.

 

 

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Close-up view of the microphone grill of the Sonotone Model 977 vacuum tube hearing aid. The grill consisted of 2 square holes hidden beneath the pocket clip.

 

 

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Rear view of the Sonotone Model 977 vacuum tube hearing aid. The whole back comprised the battery compartment door. It swung out to the left.

 

 

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Left side view of the Sonotone Model 977 vacuum tube hearing aid showing the release button to open the battery door (center) and the 3-hole jack—probably for an external microphone (right of center).

 

 

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View of the right side of the Sonotone Model 977 vacuum tube hearing aid showing the battery compartment door hinge.

 

 

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Inside view of the empty battery compartment of the Sonotone Model 977 vacuum tube hearing aid with the battery compartment door swung out to the left. It only swung out 90°.

 

 

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View of the  inside of the lid of the battery compartment of the Sonotone Model 977 vacuum tube hearing aid (left) showing the make (Sonotone) and the model number (977). Below that is "Sonotone Corporation/ Elmsford, New York/Made in U.S.A." At the bottom is "See patent notice in instruction book".

On the right is the battery compartment showing the  30 volt "B" battery (Eveready No. 507E) (center) and the 1.4 volt mercury "A" battery  (Mallory No. RM-1) (bottom right).

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Close-up view of the bottom right corner of the Sonotone Model 977 vacuum tube hearing aid battery compartment showing the serial number (531109) (left) and the "A" battery. (right)

 

 

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Inside upper view of the battery compartment of the Sonotone Model 977 vacuum tube hearing aid showing the low cut (1-2) adjustment (right)

The low-cut filter helped cut out the louder low-frequency sounds if they were bothersome.

 

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Side view of the low-cut filter of the Sonotone Model 977 vacuum tube hearing aid shown in the "2" position.

 

 

 

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Inside lower view of the Sonotone Model 977 vacuum tube hearing aid showing the high cut (A-B) adjustment (left) and the 3-position "cushion" adjustment (center).

The high-cut filter cut out the sharper high-frequency sounds if they were bothersome.

It is unknown exactly what the "cushion" adjustment was for.

 

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Edge view of the receiver and receiver cord plug of the Sonotone Model 977 vacuum tube hearing aid showing the receiver cord unplugged.

Note the unusually long pins on the receiver cord plug.

 

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Rear view of the receiver for the Sonotone Model 977 vacuum tube hearing aid showing the receiver cord plugged in.

 

 

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Side view of the receiver and ear mold for the Sonotone Model 977 vacuum tube hearing aid showing how they snapped together.

 

 

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Front view of the receiver of the Sonotone Model 977 vacuum tube hearing aid showing it unsnapped from the ear mold (left).

This hearing aid was donated by Ruth Bott in memory of her mother, Helen York of White Plains, NY who wore it.

 


 

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