A bit of background and an explanation of how analog devices work versus how digital devices work is necessary to understand the differences between analog and digital hearing aids. Analog hearing aids came out 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. The majority of (up to 90%) hearing aids purchased in the US at this point are digital, although you can still find analog hearing aids because some people prefer them, and they’re typically less expensive.
Analog hearing aids handle incoming 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. On the other hand, 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 “bits and bytes” that all digital devices understand. This digital information can then be altered in many sophisticated ways by the microchip inside the hearing aid, prior to being converted back into ordinary analog signals and sent to the speakers.
It is important to remember that analog and digital hearing aids serve the same purpose – they take sounds and boost them so that you can hear them better. Both varieties of hearing aids can be programmed by the dispensers of the hearing aids to produce the sound quality desired by the user, and to create configurations appropriate for different listening environments. The programmable hearing aids can, for instance, have one particular setting for use in quiet rooms, another setting for listening in noisy restaurants, and still another for listening in large auditoriums.
But beyond programmability, the digital hearing aids often offer more controls to the user, and have more features because of their ability to manipulate the sounds in digital form. They have an array of memories in which to save more environment-specific settings than analog hearing aids. They can also employ sophisticated rules to identify and reduce background noise, to eliminate feedback and whistling, or to selectively detect the sound of voices and “follow” them using directional microphones.
As far as pricing is concerned, analog hearing aids are generally less expensive, although some digital hearing aids are approaching the cost of analog devices by removing the more state-of-the-art features. There is often a noticeable 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.