When trying to fully understand the difference between analog and digital hearing aids, you need to first understand the history of analog vs digital, and the alternative ways that they process and amplify sounds. Analog hearing aids appeared first, and were the norm in most hearing aids for many years. Then with the introduction of digital signal processing (DSP) technology, digital hearing aids also started to appear. Currently, most (90%) of the hearing aids sold in the US are digital, although analog hearing aids continue to be sold because they are often lower priced, and also 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. Digital hearing aids take the sound waves from the microphone and transform them to digital binary code. This digital information can then be manipulated in many sophisticated ways by the micro-chip within the hearing aid, prior to being transformed back into ordinary analog signals and delivered to the speakers.
Both analog and digital hearing aids carry out the same work – they take sounds and amplify them to enable you to hear better. Both analog and digital hearing aids can be programmable, meaning that they contain microchips that can be modified to adjust sound quality to match the user, and to create different settings for different listening environments. The programmable hearing aids can, for instance, have one setting for use in quiet spaces, another for listening in loud restaurants, and still another for use in large auditoriums.
Digital hearing aids, because of their ability to manipulate the sounds in digital form, generally offer more features and flexibility, and are commonly user-configurable. They have multiple memories in which to store more environment-specific settings than analog hearing aids. They can also employ sophisticated algorithms 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 continue to be less expensive than digital hearing aids, however, some reduced-feature digital hearing aids are now in the same general price range. There is commonly a noticable difference in sound quality, but the question of whether analog or digital is “better” is entirely up to the individual, and the ways that they are used to hearing sounds.