Gem Model 30 Standard "1" Carbon Hearing Aid The Gem Model 30 Standard "1" carbon hearing aid was manufactured by The Gem Ear Phone Co. of New York, NY somewhere around 1930 to 1935. There were a number of early Gem carbon hearing aids. Since Gem didn't put model numbers on these aids, and since there are few, if any, records describing each model, it is impossible to know for sure which model is which. As a result, to differentiate different similar unmarked models in the museum, I have simply given a serial number in quotes (e.g. "1") to these unknown models. Thus this Gem carbon hearing aid is "1" version of what I think is the Gem Model 30 Standard carbon hearing aid. It consisted of a microphone, earphone, volume control, battery and cords to attach these items together. This hearing aid was quite heavy for its size, weighing 12.6 oz. (358 g) with the battery. |  | Click picture for larger view | | | | |
Front view of the microphone of the Gem Model 30 Standard "1" carbon hearing aid. The microphone grill consisted of many small holes. The microphone was 2⅜" (6.0 cm) in diameter and ¾" (1.9 cm) thick. Around the rim of the microphone are the words "The Gem Ear Phone Co., New York". |  | Click picture for larger view | | |
Rear view of the Gem Model 30 Standard "1" carbon hearing aid microphone. Near the top are the words, "Made in U.S.A.". At the top of the microphone is a hole for threading a cord through so you could hang the microphone around your neck if so desired. |  | Click picture for larger view | | |
The Gem Model 30 Standard "1" carbon hearing aid was rather unusual in that it had a separate volume control. It could be used with or without the volume control. The volume control had an 8-position wheel to set the desired volume. |  | Click picture for larger view | | |
The volume control of the Gem Model 30 Standard "1" carbon hearing aid mounted directly on the battery pins. |  | Click picture for larger view | | |
View of the Gem Model 30 Standard "1" carbon hearing aid showing how the microphone (top), the volume control (middle) and the battery (bottom) fit together when using the volume control feature.
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View of the Gem Model 30 Standard "1" carbon hearing aid showing how the microphone (top) and the battery (bottom) fit together when not using the volume control feature. This hearing aid used a Gem 1A 3-volt battery. |  | Click picture for larger view | | |
Another cool feature of the Gem Model 30 Standard "1" carbon hearing aid was that you could "hide" the battery in your pocket by using the microphone extension cord. This way you wouldn't have the weight of the battery hanging around your neck with the microphone attached. The microphone extension cord was about 16" (40.5 cm) long. |  | Click picture for larger view | | |
You could use the microphone extension cord with or without the volume control. It is shown here hooked up to the volume control.
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Front view of the earphone for the Gem Model 30 Standard "1" carbon hearing aid. The earphone measured 2 1/16" (5.2 cm) in diameter by ⅞" (2.2 cm) thick. It was quite heavy for an earphone, weighing 2.5 oz (72 g). |  | Click picture for larger view | | |
Rear view of the Gem Model 30 Standard "1" earphone showing the "On" and "Off" positions for the switch (top).
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Side view of the Gem Model 30 Standard "1" carbon hearing aid earphone showing the on-off switch on the side (bottom) in the "On" position. The hole on the left bottom is where the headband (missing) for the earphone snaps in. There is a corresponding hole on the other side of the earphone. |  | Click picture for larger view | | |
The Gem Model 30 Standard "1" carbon hearing aid in its carrying case.
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The top of the Gem Model 30 Standard "1" carbon hearing aid carrying case reads "The Gem Earphone Co., New York"
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The Gem Model 30 Standard "1" carbon hearing aid carrying case was finished in black leatherette. The case measured 7½" (19.0 cm) by 1 15/16" (7.5 cm) by 1¾" (7.1 cm) high.
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