Compression is a feature of some hearing aids which attempts to change the amount of gain that the amplification circuits add to the incoming signal to better fit the wearer's needs.

Compression is especially valuable when the hearing loss results in a reduction in the dynamic range or recruitment.

There are several types of compression techniques:

• compression limiting
• dynamic range compression
• frequency dependent compression
• curvilinear compression
• multiple channel compression

You can learn more about each by clicking on their link, but they represent different levels of sophistication or approaches to tweaking the amount of gain for various circumstances.

Compression is sometimes confused with clipping, so you might also want to check out what that means.

If the compression setting on your aid is not right, you may experience certain noise situations where the aid seems to temporarily shut down or even rapidly cycles between on and off, giving you almost a "thumping" feeling.

The sophistication of compression circuitry varies a lot. Less sophisticated solutions typically offer fewer fine tuning adjustments to shape the response than more sophisticated solutions. Less sophisticated solutions may also have a noticeable delay in the reaction and recovery times when a compression even occurs.

It's powerful technology and it pays for hearing aid wearers to understand at least enough about it to explain to their hearing health care professiona what they are hearing.