When trying to fully understand the difference between analog and digital hearing aids, you need to first appreciate the history of analog vs digital, and the different ways that they process and amplify sounds. Historically, analog technology emerged first, and as a result most hearing aids were analog until digital signal processing (DSP) was invented, after which digital hearing aids appeared. Most (roughly 90%) hearing aids sold in the United States at this point are digital, although you can still find analog hearing aids because some people have a preference for them, and they are typically cheaper.
Analog hearing aids handle inbound sounds by taking the electrical sound waves as they leave a microphone and amplifying them “as is” prior to sending the sound waves to the speakers in your ears. Digital hearing aids take the sound waves from the microphone and convert them to digital binary code, the “bits and bytes” and “zeros and ones” that all digital devices understand. This digital data can then be manipulated in many complex ways by the micro-chip inside the hearing aid, before being converted back into regular analog signals and delivered to the speakers.
Analog and digital hearing aids carry out the same work – they take sounds and boost them to enable you to hear better. Both analog and digital hearing aids can be programmable, meaning that they contain microchips that can be customized to adjust sound quality to match the user, and to develop various configurations for different environments. The programmable hearing aids can, for example, have one particular setting for listening in quiet rooms, another for listening in loud restaurants, and still another for use in large stadiums.
Digital hearing aids, due to their ability to manipulate the sounds in digital form, often offer more features and flexibility, and are commonly user-configurable. For example, digital hearing aids may offer multiple channels and memories, allowing them to store more location-specific profiles. They can also employ advanced algorithms to identify and minimize background noise, to eliminate 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. There is often a perceivable difference in sound quality, but the question of whether analog or digital is “better” is up to the wearer, and the ways that they are used to hearing sounds.