Last week’s blog described somewhat my dilemma about what to do with some of the “stuff” related to hearing aids that I have accumulated over the years. I did offer some suggestions, and one that I thought might draw overwhelming attention, related to selling some of this. And, I know that it is almost impossible to believe, but I have yet to receive a single offer for any of my “stuff.”
The blog went on to show a randomly-selected small container in one of the MANY drawers that I have to illustrate what I was talking about. I mentioned that I would describe the contents of what I had spread out in this week’s blog. So, let’s start to describe some of these “jewels” that I have not yet parted ways with.
Item #1 is a small bottle of oil in which each of the auditory ossicles floats. The stapes, incus, and malleus are readily visualized. Don Schaefer, a classmate, gave these to me in graduate school at the University of Wisconsin – Madison in about 1964. These are actual ossicles, not models. How he came to have these is something I don’t know. However, I hope that the person they came from is not running around.
Item #2 is part of the temporal bone that houses the cochlea and the semicircular canal. Over the years some students have “poked around” enough to have enlarged the round window beyond its normal size, bit it is easily differentiated from the oval window where the stapes has its articulation. Again, this was given to me in about 1964.
Item #3 is perhaps one of the most useful items I have owned when it comes making rapid listening comparisons of two different hearing aids. The hearing aids are attached to the two long polyethylene tubes. A listening tube is attached to the nubbin on the center far side for either the patient or the dispenser. The small rod lever at the bottom, when rotated from one side to the other, allows for rapid switching between listening to the two attached hearing aids. A hole in the rotating center core aligns with either one or the other of the tubes from the hearing aid as the lever is moved from one side to the other. There is a built-in stop to ensure that the holes are centered over the opening directed inward from the “b” attachments. And, for those who have no idea what a “b” attachment is, it is the snap-in plastic end attached to the polyethylene tubes from the hearing aid. This is one of the best paired-comparison devices I have ever used. It is essentially a mechanical switching arrangement. I use it currently.
Item #4 is a red hearing aid made as one of the first “game detector” hearing aids. They were for Minnesota Viking football coach, Bud Grant, who was an avid hunter. The problem was that he also could not hear well enough to detect the game. We (Audiotone) were asked to build these for him by a hearing aid dispenser in the twin cities by the name of Harry Rossman. Why red? This was not a fashion statement as we attempt to show with hearing aids today, but practical so that if he dropped one, it could be seen fairly easily. This was not bad for duck and goose hunting when there was usually quite a bit of snow. But, trying to find these on the ground in the leaves in the Fall in Minnesota was a much more daunting task. Although we were involved in the initial stages of this concept, it was never finished because someone at Smith & Wesson, one of our divisions stated that “The ‘Game Detector,’ off the top of my head, would seem to be a good idea, but a very limited market for the sporting goods side of our business. Our normal channels of distribution are not tuned in to this type of product.” It has subsequently been manufactured by other hearing aid companies. This was another example of a product and idea ahead of its time. The year was 1984.
Item #5 was a “Presidential” hearing aid made in honor of Jimmy Carter and presented to me by some of our people in the repair department. I always valued my relationship with our employees who worked on the line, and learned much from them. We had great mutual respect and outstanding relationships. As a result, they often presented me with such “jewels” as their contributions to product development.
Item #6 actually looks like an ear impression – probably because it is. But, why keep something like this around for many years? This is an old ethyl methacrylate ear impression of my mother’s poor ear, or what I would call an auras mortis. (Today’s unimaginative and medically correct would refer to this as a dead ear – when did we lose all humor?). My mother developed an auras mortis on her wedding day to what we now assume was an interruption of the blood supply to the cochlea. Only after I was employed with a hearing aid company did I start to try about every hearing aid I could to assist her hearing. She may have ended up with as many different types and arrangements of hearing aids as Amelda Marcos had shoes. The only difference was that none of my mother’s matched due to the asymmetry of her hearing levels. So, back to the question, why do I keep it? I have a sneaking suspicion that mothers always remember how their children treated them. And, even though she is long gone, I don’t want to take any chances!
Item #7 is an in-line volume control accessory for a body-worn hearing aid fitted with a “Y” cord to both ears, and used for when the hearing loss was asymmetrical. Management of this asymmetry could be handled in two different ways: an acoustic filter in the button receiver of the better ear, or the use of a balancing rheostat or potentiometer in the “Y” cord. The latter could provide as much as 30 dB gain reduction. They were available in either a two-terminal or three-terminal arrangement.
Item #8. Yes, eyeglass hearing aids actually did exist. In fact, the eyeglass hearing aid’s history preceded the BTE hearing aid. In the early days the temple extensions to eyeglasses used either 5 or 7-barrel hinges. A variety of temples were available, but eyeglass hearing aids started to lose in popularity as eyeglass frames and temples became smaller, lighter, and as hinge arrangements changed. As a result, it became more difficult to attach the actual hearing aid electronics to the temple. In some designs the hearing aid actually attached to the end of the temple with some kind of bayonet arrangement, but in other cases the hearing aid electronics were actually embedded in the temple. With the latter, barrel attachments as shown in the top of the photo required different barrel lengths. What is shown is a measurement device to select the appropriate barrel length. Most companies stopped manufacturing hearing aids in the late 1970s and early 1980s.
Item #9. When direct audio inputs (DAI) to hearing aids started to become popular, many hearing aids did not have this as a built-in feature. Additionally, older hearing aids could not be retrofit for DAI. As a result, some manufacturers designed a small, flat device that could be physically attached to the side of the hearing aid using a small rubber band and the other end attached to the external device. This was essentially a remote external electromagnetic induction to the hearing aid telecoil. This was in about the early 1980s.
Item #10. And what in-the-ear hearing aid would be complete without an over-the-ear adapter? This was especially important if the hearing aid (stock unit) did not fit securely into the ear. This attachment solved the problem. An additional by-product was that this combination allowed for a small BTE hearing aid. The earhook was a friction fit. This was about in the early 1970s.
Item #11. I am not certain that I can remember all that we used this for. However, I remember us using this with some of the first digital hearing aids we built (1983). The digital hearing aid at that time required a body-worn unit because of the size of the power supply and the number of DSP chips in the unit. A cord connected the body unit to a BTE hearing aid using the small two-pin connectors. This block allowed us to plug into the processor (mini stereo plug). The hearing aid was attached by a cord via the gold female connections. The switch allowed us to change the hearing aid into either a “standard” hearing aid performance or into a “noise cancellation” mode. The BTE unit actually used two different microphones for noise cancellation. The forward facing microphone was an omnidirectional mic. The rearward-facing microphone was a single unit directional microphone. However, what was unique about this, and duplicated by others working on digital hearing aids in the 1990s, but who never referenced our original work, was that we used the directional microphone backwards so that it would pick up its greatest signal from the rear. Why did we do this? The reason was because we were using a LMS filter (least means square) in the unit to cancel out the noise and we needed to make the forward and rear signals as different as we possibly could so that the filter could function more effectively and “zero” out the noise. This small block allowed us to switch the directional microphone either in or out, which we then actually designed into the digital hearing aid. You will notice also a couple of small potentiometers which were used for frequency response adjustment.
Item #12. Any person who used the old Radioear hearing aids will identify this box immediately as one of many that filled a larger plastic container from the Radioear hearing aid company. Radioear (a company that Sam Lybarger, the father of hearing aids held ownership in) designed hearing aids so that dispensers could make repairs in their offices without having to send the instruments back to the factory, if they so desired. These small plastic containers held, and identified, the parts to match with repair instructions.
Item #13. This is a “Y” cord for a body-worn hearing aid by which an electrical signal from one amplifier of a body hearing aid is provided to two earphones and delivers amplified sound to both ears of the user. The “Y” cord was wired in two different ways: parallel, or series. Hearing aids had to be specifically designed for good “Y” cord performance due to load impedance.
Item #14. This is a reminder to me of the repair form comment associated with this hearing aid. “Please advise if this instrument has any salvage value. It was worn by an 80-year old virgin on her wedding night. She claims the instrument sizzled and popped and became extremely hot before going completely dead. She has been fitted with a new Audiotone with implicit instructions to remove the instrument before going to sleep.” I ask you, how could one possibly toss away something rendered as emotional as this?
Item #15. ELBA. Ear Level Bilateral Attachment. This is for a single BTE hearing aid with the output being directed to both ears through hollow polyethylene tubing. In a sense, this was the conventional Y-cord aid’s ear-level counterpart.
Item #16. Directional microphone hearing aid. Another of our repair department’s attempts at designing hearing aids. Note the user-adjustable wheel in the side of the case to turn the satellite dish extending from the rear of the case to its best operational direction.
Item #17. Special soft, open stock earmolds that had lamb’s wool plugged vents. These attached with a “b” adapter to the hearing aid. The photo shown is a a unit used in hearing aid evaluations. These could be molded into custom earmolds as well. Zenith Hearing Aid Company and was suggested for high-frequency hearing losses.
Now, after hearing these stories, tell me which of these “jewels” you would toss?