Since I have complete hearing loss (as a result of a childhood fever) in my right ear, I'm fitted with a "bi-cross" aid. It picks up sound on the right side of my head and transmits it to the aid on my left side that combines that sound with the input from the microphones on the left and feeds the blended product into the ear canal of my good ear.
These are my new hearing aids. The one on the right goes to my right (deaf) ear. If you look closely, you see the part that connects the earpiece to that hearing aid is just a clear plastic tube. Again, if you look closely, you see that the earpiece is a piece of clear plastic covered with the rubber dome that holds it in place in my ear canal. The only job of that earpiece is to hold, via the molded plastic tube, the hearing aid in place behind my right ear.
The purpose of the right side hearing aid is to pick up sounds on that side and transmit them to a receiver in the hearing aid for my left ear.
Now to the hearing aid for my good (left) ear. The aid on this side has two microphones just as does the one on the other side but in addition to amplifying the sound picked up from this side it also melds it with the sound transmitted from the other side so I hear one stream of sound.
If you look at the plastic connecting tube on the left you see it contains a thin wire that carries the sound data to the small speaker that you can see in the earpiece.
The rubber dome makes it more comfortable to wear that foreign object inserted into the ear. In addition, the small holes in the dome allow natural sound to get through to the eardrum. The little plastic tails going off to the bottom of the frame are designed to curl around the inside of the exterior ear and stabilize the business parts that are worn behind the ears.
I have been pleasantly surprised to find that the first set of batteries for this newer aid lasted almost exactly seven days. The same batteries in the old hearing aids lasted only two to three days. When I complained about the short lifespan, the technician told me it was because my hearing loss is substantial thus requiring more amplification and the aids are the bi-cross model which takes more power. The batteries are the same so there must have been big improvements in power use.
Next came the fitting and tuning. This was the magical time when I sat it front of a monitor, the technician inserted a tiny microphone into my ear canal and tuned the aids to match my hearing loss.
I'm not sure what it's called by the hearing specialists, but by tuning the hearing aids, I mean adjusting the amplification so that sounds in the upper frequencies, where my loss is greatest, are amplified the most. Sounds in the lower frequencies, where my hearing has not suffered as much loss, are amplified less. The desired result of this tuning is more or less equal sound perception no matter where on the frequency spectrum any particular sound might fall.
When I first tried this type aid about seven years ago I was amazed at the sounds I had been missing. From the calls of the little birds in my backyard to the high pitched beeps emitted by many electronic devices people use everyday, I missed out on those sounds for many years.
I've been missing high frequency sounds for many years because the primitive bi-cross aids I was given in 1979 and the ones I purchased in 1986 were basically nothing more than speakers with adjustable volume controls that amplified all sounds indiscriminately. I couldn't wear those aids for long because the loud low pitched sounds drove me crazy if I adjusted the volume loud enough to hear the high pitched sounds. I wasn't the only person with that complaint and it was common for people to buy hearing aids only to put them in the drawer until their hearing became so bad they had no choice but to wear them if they wanted to hear anything.
Of course, even though these are wonderful tools, because I have only one working ear I can't tell where a sound comes from. Your ears are designed so the small phase difference in the sound wave as it hits the ears on different sides of your head lets your brain tell the direction of the sound. This sound locating ability that works so well for most of the population doesn't do anything for a one-eared person like me. Even people who know the theory will answer, "Right over here." when I ask, "Where are you?" It would be much better if they would give a description, "In the kitchen, upstairs, next to the bandstand," etc., but old habits that work so well with most people are hard to modify.
Here's another part of the amazing package of electronics that allows me to get the most out of my limited hearing.
This gizmo (ComPilot, to use its proper name) is worn on my chest dangling from the cord (also the antenna) that goes around my neck. This unit is synced to my cell phone and relays that signal to my hearing aid. It has its own microphone so I can carry on a hands-free conversation. The large square button on its face is the switch that answers or ends calls or redials the last call made. There are volume controls and syncing controls and an on-off switch. There are also ports for charging, connecting to external devices and one to connect to Roger/FM (Europlug)
I'm just getting to know this new ComPilot but find that in addition to what I've listed, it can forward calls, voice dial, dial a pre-programmed preferred number, hold calls and more. I've already ordered an external microphone which clips to my collar and allows me to wear the ComPilot under my shirt.
A new and especially nice feature for people like me who only have one ear and thus are unable to hear in stereo, is the wire shown on the left, above. This wire plugs into the ComPilot and connects to any number of devices. It will plug into my cell phone, a TV, an MP3 player or the seat sound plug on airplanes among others, and combines the stereo output of the remote device to a monaural input to my hearing aid thus allowing me to hear both tracks of stereo music or conversation. I anticipate that this feature will be useful on flights where I can watch movies or such and actually hear both sides of the stereo sound track. I'm anxious to try it out.
So far I'm happy with the set up. What a boost to my hearing.
Now if they could just figure out how to give me stereo hearing again.
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