A little bit of history and an explanation of how analog devices work versus how digital devices work is essential to understand the differences between digital and analog hearing aids. Analog technology emerged first, and consequently most hearing aids were analog until digital signal processing (DSP) was invented, after which digital hearing aids appeared. At this point, the majority (90%) of the hearing aids sold in the United States are digital, although analog hearing aids are still sold because they are often less expensive, and because some people prefer them.
Analog hearing aids handle incoming sounds by taking the electrical sound waves as they leave a microphone and amplifying them “as is” before sending them to the speakers in your ears. In contrast, digital hearing aids utilize the very same sound waves from the microphone, however before amplifying them they turn the sound waves into the binary code of ones and zeros that all digital devices and computers use. Once the sound has been digitized, the microchip within the hearing aid can manipulate the data in sophisticated ways before converting it back to analog sound and delivering it to your ears.
Remember that both analog and digital hearing aids serve the same purpose – they take sounds and amplify them so that you can hear them more easily. Both analog and digital hearing aids can be programmable, which means that they contain microchips which can be customized to adjust sound quality to suit the user, and to create different configurations for different listening environments. For example, there can be different settings for quiet locations like libraries, for busy restaurants, and for large areas such as stadiums.
But beyond programmability, the digital hearing aids often offer more controls to the wearer, and have additional features because of their capacity to manipulate the sounds in digital form. They have an array of memories in which to store more environment-specific configurations than analog hearing aids. They can also use sophisticated rules to detect and minimize background noise, to remove feedback and whistling, or to selectively prefer the sound of voices and “follow” them using directional microphones.
Price-wise, most analog hearing aids are still less expensive than digital hearing aids, however, some reduced-feature digital hearing aids fall into the same general price range. Some users notice a difference in the sound quality generated 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.”