Hearing Haven
Digital vs. Analog - What's The Difference?
Learn the differences explained below between digital and analog hearing aids, and you will be more knowledgeable than most people,
even more than some hearing professionals!
Analog
Analog hearing instruments amplify the sound wave by simply making it larger. They use transistors in a circuit to amplify and modify the incoming sound. Any changes to the sound of the hearing aid are made with the volume control, small trimmers to adjust the response, or by sending the aid back to the manufacturer to have components changed.
Advantages of analog hearing aids
- Long time hearing aid users sometimes find the sound more acceptable because they are used to it.
- Cost is much less than digital.
- Batteries usually last longer.
- Are sometimes more powerful than digital.
Programmable
Programmable hearing aids can have their response (sound) changed in the dispenser's office rather than sending it back to the factory. If you need more power, a change in frequencies, or other changes, the hearing aid fitter can plug a cord into your hearing aid and modify it on the spot. Some programmable hearing aids are analog, not digital.
Advantages Of Programmable And Digitally Programmable
- Sound and results can be changed in dispenser’s office without shipping back to manufacturer.
- Less expensive than DSP (digital signal processor) digital.
- Sound can be adjusted to better fit your own likes and dislikes.
A digitally programmable hearing aid may still be analog, not digital. The first use of digital technology in hearing aids was to use a digital function to change the sound of the hearing aid. These hearing aids are often still analog hearing aids; they just use digital programming to make changes to the sound. A hearing aid that is truly a digital hearing aid is referred to as “DSP”, for digital signal processing.
True Digital or DSP (digital signal processor)
A true digital hearing aid (DSP, or digital signal processor) takes the incoming signal from the microphone, converts it into a digital format, and then processes the signal using digital technology before converting it back into an analog sound to be delivered to your ear. Digital hearing aids are normally much more flexible and can be used to process sound more selectively than an analog.
Advantages of DSP
- Certain “noise reduction algorithms” can be programmed into the circuit to help reduce background noise.
- Digital feedback reduction can make more gain available without whistling occurring.
- Some instruments are able to have multiple memories for different listening situations.
- Some instruments select and follow the sound of voices with a self-focusing directional microphone.
- The greatest degree of flexibility in adjustments is available with a good instrument.
Caveats (Warnings!)
Some low priced digital hearing aids have reduced or eliminated most of the benefits above to cut the cost. Just because it is advertised as “digital” does not mean it is a quality product. Sometimes you may experience better sound quality with an analog aid than with a budget digital. A high-end, high quality digital instrument can sound terrible if programmed incorrectly by the fitter. The complexity and flexibility create a steep learning curve to the dispenser. Ask the dispenser how long he has been fitting the aid he is promoting. Don’t be a guinea pig. Just because it is expensive does not mean it is a good hearing aid. Read about different brands on the Internet or in a library. Talk to hearing aid users to find out their experiences.
Digital Hearing Aid Definitions:
Bands
Frequency ranges that can be adjusted individually. A good analogy can be made with a graphic equalizer on your stereo system. When connected to the computer, an digital hearing aid can have different frequency bands of gain adjusted up or down separately, much like you would slide a control on your stereo to increase or decrease levels sound at different frequency ranges. An entry-level digital may only have one or two bands, which can be adjusted separately, whereas a more adjustable instrument may have 4, 9, 10, 12, or even 16 adjustable frequency bands.
Memories
Each memory of a multi-memory hearing aid can be programmed independently to function for its specified use. You change between memories by pressing a button on the aid, using a remote control or a magnetic wand. Typically one memory will be for normal conversation or television in a quiet setting and one memory will be programmed for noise reduction. Other choices would be telephone usage and music memories. Typically multi-memory hearing aids will have two, three, or four memories.
Channels
Similar to bands, except that channels are frequency ranges in which compression settings, not gain, can be adjusted individually. A person may have a sensitivity to loud high pitched sounds, for instance, and the hearing professional may choose to use more compression in the high frequency channel to provide comfort in that frequency range without having to compress sounds in other ranges of speech.
