When trying to understand the difference between analog and digital hearing aids, you need to first understand the history of analog versus digital, and the different ways that they process and amplify sounds. Analog hearing aids came out first, and were the norm in most hearing aids for a long time. Then with the arrival of digital signal processing (DSP) technology, digital hearing aids also started to appear. At this point, the majority (90%) of the hearing aids purchased in the US are digital, although analog hearing aids continue to be offered because they’re often lower priced, and because some people prefer them.
The way that analog hearing aids operate is that they take sound waves from the microphone in the form of electricity and then amplify them, delivering louder versions of the sound waves to the speakers in your ears “as is.” In contrast, digital hearing aids utilize the very same sound waves from the microphone, but before amplifying them they turn the sound waves into the binary code of ones and zeros that all digital devices use. After the sound is digitized, the micro-chip within the hearing aid can process and manipulate the information in sophisticated ways before converting it back to analog sound and passing it on to the ears.
Both analog and digital hearing aids carry out the same function – they take sounds and boost them to enable you to hear better. Both varieties of hearing aids can be programmed by the dispensers of the hearing aids to produce the sound quality that each user desires, and to develop settings appropriate for different listening environments. The programmable hearing aids can, for example, have one setting for use in quiet spaces, another setting for listening in noisy restaurants, and still another for use in large stadiums.
Digital hearing aids, because of their ability to manipulate the sounds in digital form, often have more features and flexibility, and are commonly user-configurable. For example, digital hearing aids may offer multiple channels and memories, allowing them to save more location-specific profiles. They can also use sophisticated rules to identify and reduce background noise, to remove feedback and whistling, or to selectively detect the sound of voices and “follow” them using directional microphones.
Cost-wise, most analog hearing aids are still less expensive than digital hearing aids, but some reduced-feature digital hearing aids are now in the same general price range. Some users notice a difference in the sound quality produced by analog vs digital hearing aids, although that is largely a matter of personal preference, not really a matter of whether analog or digital is “better.”