Types of Hearing Aids
 
At one level, all hearing aids work the same. There is a microphone that picks up the sounds, an amplifier, and a receiver that returns the sound to the ear.

There are, however, different ways of achieving this -- and different ways of controlling which sounds get amplified and how.

The Analog Adjustable is the least expensive type of hearing aid. It works by collecting the sound in a microphone, which converts the sound waves to an electrical signal. The signals are amplified and then sent to the ear via a receiver.

In short, it's a loudspeaker system.

The aid is built at the factory according to the specifications of the audiologist, who will make a prescription based on your needs.

When using aids of this type, users can generally turn the volume up or down, depending upon their need.

Analog Adjustable aids generally cost from $400 to $900 USD.
Analog Programmable hearing aids are the next step up in both price and sophistication.

Adjustments to these aids can either be done by an audiologist, or -- on some models -- by the user through switches or a remote control. They can divide the sound into a couple of separate bands -- say high and low, and process the two differently.

Generally, this makes the hearing aid more useful in a wider variety of situations.Many of these models have automatic volume controls.

They are more flexible than straight analog hearing aids, and sometimes will require several visits to the audiologist to get things just right. (Mine took quite a few trips)

The cost of an analog programmable aid typically is $1300 to $1700 USD.
Digital Programmable aids are the latest computer-age innovation. These aids collect the sound in a microphone and then convert the sound to digital signals. These digital signals can be split into separate bands, and processed separately according to the needs of the user. The signal is then reconverted and sent back through a receiver to the ear.

Digital aids address the most common problem with hearing aids: that they increase the volume of all the sounds, not just the ones that the wearer needs help with. Properly programmed by the audiologist, they provide better sound -- less distortion -- than other aids. There also is less noise from circuitry.

Some digital aids also have directional microphones that allow you to change the direction of the focus. So, if you are having a conversation with someone in a crowded room, the microphone can be used to focus in that direction. Others will adjust themselves automatically as they sense different situations.

Disposable Hearing Aids are another recent innovation. With these, you buy an aid that lasts for several months, and then throw it away when the battery wears out. These in-the-canal models are supposed to be one-size-fits-all, although I have never found anything that's truly one-size-fits-all.