When trying to understand the difference between analog and digital hearing aids, you need to first appreciate the history of analog vs digital, and the alternative ways that they process and amplify sounds. Analog hearing aids appeared first, and were the standard in most hearing aids for a long time. Then with the introduction of digital signal processing (DSP) technology, digital hearing aids also began to appear. The majority of (roughly 90%) hearing aids sold in the US today are digital, although you can still get analog hearing aids because some people prefer them, and they’re often cheaper.
Analog hearing aids handle inbound sounds by taking the electrical sound waves as they emerge from a microphone and amplifying them “as is” before sending them to the speakers in your ears. In contrast, digital hearing aids take the 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 understand. Once the sound has been digitized, the microchip within the hearing aid can manipulate the data in complex ways before converting it back into analog sound and delivering it to your ears.
Remember that analog and digital hearing aids have the same function – they take sounds and boost them so you can hear them more easily. Both types of hearing aids can be programmed by the dispensers of the hearing aids to create the sound quality desired by the user, and to create configurations appropriate for different environments. As an example, there can be different settings for quiet locations like libraries, for noisy restaurants, and for outdoor spaces such as sports stadiums.
Digital hearing aids, due to 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 numerous channels and memories, permitting them to save more environment-specific profiles. They can also employ advanced rules to detect and reduce background noise, to eliminate feedback and whistling, or to selectively detect the sound of voices and “follow” them using directional microphones.
In terms of price, analog hearing aids are in most cases less expensive, although some digital hearing aids are nearing the price of analog devices by removing the more state-of-the-art features. There is commonly a perceivable difference in sound quality, but the question of whether analog or digital is “better” is up to the individual, and the ways that they are used to hearing sounds.