My past two posts on old hearing aids have followed an historical theme based on a box of old hearing aids I uncovered in my garage recently. I actually knew they were there, but digging them out was not high on my list. However, they were uncovered when I was looking for a baling hook (unrelated to hearing aids). And, who can resist the temptation to open a box titled “Old Hearing Aids,” especially when they included what might have been among some of the first ITE hearing aids?
The initial post on these old hearing aids related mostly to eyeglass hearing aids (a hot item in its time and given substantial promotion because Eleanor Roosevelt wore eyeglass hearing aids). Last week’s post featured some of the first behind-the-ear hearing aids taken from that box.
Because the box had some additional goodies in it that had not been covered in my previous writings, this post will discuss and show some of the first in-the-ear hearing aids.
In-The-Ear Hearing Aids
It should come as no surprise to anyone working with hearing aids that the market has always been driven by cosmetics, and this relates to making hearing aids as unobtrusive as possible, meaning making them as small as possible. In the early days, these were not referred to as in-the-ear hearing aids, but as “at-ear” hearing aids.
This unit from my box leads the way to the at-ear hearing aid category (Figure 1). No identification was found on this hearing aid. However, it did use a 625 cell, indicating that it used transistors of the early stages, which would put this into the early to mid 1950s. All the components, except the receiver and power supply, are contained in the larger round section. The external receive is of the smaller size, and attached to the inner side of the hearing aid in such a way that it is embedded into the custom-made earmold. There are no controls on the instrument. Operation occurs with the insertion of the battery/cell.
If anyone has knowledge of this hearing aid, I would appreciate hearing from you.
Dahlberg Miracle Ear Model D-10 (1955)
This was called an “at ear” hearing aid, and consisted of a 3-transistor unit powered by a 400 cell. It measured 41 x 18 x 16 mm and weighed 15 grams. This may possibly have been the first commercially-made at-ear hearing aid (Figure 2). This seems to be the first product that Dahlberg identified as “Miracle Ear,” a trademark that was one of the most recognized hearing aid names among hearing aids by the general public. Prior to this, Dahlberg had used the “Magic Ear” name. A custom earmold having a snap ring was attached to the speaker nub for retention to the concha structures of the ear. Because the earmold could swivel in the receiver nub, the body of the hearing aid could be rotated and positioned were it was the most cosmetic and/or secure.
Telex 222 (1957)
The Telex “Tynamite” at-ear hearing aid was a 4-transistor device powered by a 400 cell. It measured 24 x 16 x 18 mm and weighed 9 grams (Figure 3). The height measurement includes the receiver portion, and the weight is with a power cell. The model number (222) is stamped onto a thin transparent cover over the receiver face. The 222 had an On/Off switch on the bottom and a volume control slider at the top of the aid. The microphone opening was on the upper outside surface of the instrument.
Acousticon A-410 “Receiv Ear” (1960)
This at-ear instrument was a 2-transistor hearing aid powered by a 400 cell (Figure 4). It had no volume control. The On/Off was controlled by removing the battery from the hearing aid, which was a friction fit contact. This metal-cased hearing aid was made in England and measured 20 x 19 x 15 mm and weighed 10 grams.
Otarion ECA-1 (1961)
This was an ear canal hearing aid, also identified as the “Normalizer.” It was a 3-transistor hearing aid powered with a 312 cell in a pull-out battery holder, which also acts as the On/Off. It was available in either a left or right version. It had a volume, but no other controls. It came with an assortment of removable, friction fitting tips (Figure 5).
Zenith Solitaire (1964)
This was a custom-like in-the-ear hearing aid (Figure 6). The electronics were housed in a stock metal shell (hard plastic covered). It used a micro-lithic integrated circuit with 6 transistors, and was powered with a silver 312 cell. The model Z (which this unit is) was for sales use. A model X was for demonstration purposes. The microphone opening was on the upper faceplate and a volume control, without On/Off, was on the faceplate as well. The battery door had to be opened to turn the aid off. This instrument is being presented because it featured extensive circuitry used at that time, and because of the custom-like metal shell.