Hearing Aids

Technology & Change

Recent Advancements

One of the more recent advancements hearing aid technology has taken advantage of is digital signal processing (DSP). Compared to analog aids they allow more precise control over a broad range of sound environments. The basic difference is that while analog technology takes a signal and amplifies it, DSP technology converts signals into a digital format using an analog-to-digital converter. By doing this the signal can be manipulated and enhanced in the digital format using quite sophisticated programs and algorithms. The signal is then converted back to analog. Common with digitally controlled hearing aids is the ability to externally program them by the dispenser. They can be adjusted for gain, output and frequency response. Aids with multiple channels can be programmed individually including compression for each frequency channel. As expected, these types of hearing aids are typically more expensive.

Other terms you will come across in hearing aid discussions are multi-band hearing aids and wide dynamic range compression (WDRC). Simply put WDRC is circuitry that allows you to hear soft sounds softly where you may not have heard them before and loud sounds loudly, but tolerable. This feature can even reduce the need to have a volume control because it automatically and rapidly changes the gain adjustment. This may be helpful if you have trouble changing the volume on the smaller aids. Its certainly far more complicated than this one liner, but it's just another example of how technology today has improved the quality of todays hearing aids.

Changing Features

As you move from the economy or discount hearing aids to the upper end hearing aids these are some of the features that become available;

Often part of the basic aid;

• Output Limiting Compression or Peak Clipping - to limit maximum sounds.
• Gain Control - to adjust volume.
• Frequency Response Control – provider adjusted frequencies.
• T Switch – to pick up magnetic fields rather than sound waves for phone use.

Not always available without a charge;

• Electrical Audio Input – allows plug in capability to radios, TV or FM systems. Usually available only on BTE units.
• Remote Control – allows remote changing, ie volume & T switch.
• Wide Dynamic Range Compression – controls volume automatically.
• Directional Microphone – improved frontal hearing.
• Computerized or Digitally Programmable – ability to attach to a computer to adjust controls precisely rather than using a small screwdriver.

Normally come at a higher cost;

• Multi-Band or Multi-Channel Compression - different frequencies are processed automatically to your environment.
• Multi-Memory or Multi-Program – having several programs treating sound differently depending on the environment.
• Multi-microphone – your choice between a directional or all-around (conventional) microphone selection.
• Full Digital – provides much more flexibility to adjust the aid and more automatic control and amplification in changing sound environments.

It's just like buying a car, some hearing aid manufacturers offer different combinations of options in the basic to higher end packages. Determine what you 'need' as opposed to what you may 'want' before making the final purchase.

In the future you can continue to expect hearing aids to be smaller, to have more features, and more of them becoming part of the basic package. Hearing aids today are much better than just a few years ago.