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!

Home Enter the Museum About Us Contact Us

FREE Subscription to:
Hearing Loss Help
The premier e-zine for people with hearing loss

Your email address
will never be
rented, traded or sold!

Your First Name:
Your E-mail:
Search this site:

 Results per
 page

 all words
 any words


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

 

Carbon Hearing Aids: 1900-1939

Siemens Model 23 Carbon Hearing Aid

The Siemens Model 23 carbon hearing aid was made by Siemens & Halske A. G. of Germany around 1925.

It appears to be the quad-microphone version of the double-microphone Siemens M-22 carbon hearing aid.

Unfortunately, the battery cord/ earphone cord and receiver/earmold are missing, but it is highly likely that these items are quite similar to these same items on the Siemens Model M-22 which you can see here. It probably also used the same battery, a 4½ volt Fortiphone No. 3-S battery.
 

Click picture for larger view

 

Back Next

 
The front of the Siemens Model 23 carbon hearing aid quad-microphone. Each microphone grill consisted of an outer circle of 12 diamond-shaped cut-outs and an inner row of alternating diamond-shaped cut-outs and small circles.

The quad carbon microphone assembly measured 4¼" square x ⅞" thick. It weighed 7.2 oz.

Note the leather button-hole (top). This way the microphone could be attached to any button on the wearer's clothes. Alternately, a ribbon could be threaded through the button hole so the hearing aid could be worn on a lanyard around the wearer's neck.

Click picture for larger view

 
Rear view of Siemens Model 23 carbon hearing aid microphone. Engraved on the back just below the leather button hole are the words "Siemens & Halske A. G. Germany"

 


Click picture for larger view

 
Side view of Siemens Model 23 carbon hearing aid microphone showing the 2 jacks for the battery/earphone cord plugs.

Quad-microphones provided more amplification that single or double microphones. Hence, they were the "power aids" of the day.


Click picture for larger view

 

Side view of the Siemens Model 23 carbon hearing aid microphone showing the foot folded in place for use when wearing it on a lanyard or fastened to a button.

 


Click picture for larger view

 

Bottom view of the Siemens Model 23 carbon hearing aid microphone showing the "foot" swung out so it could stand upright on a table instead of laying flat (see top picture).

It is easy to forget that carbon microphones only worked when held vertically. When laid down, the carbon shot didn't touch both contacts on the microphone. Hence no current flowed and the hearing aid didn't work.

 


 

Click picture for larger view

 

(If a larger picture doesn't appear, you may have to turn your pop-up blocker off)