When trying to understand the difference between analog and digital hearing aids, you need to first understand the history of analog versus digital, and the different ways that they process and amplify sounds. Analog hearing aids came out first, and were the norm in the majority of hearing aids for a long time. Subsequently, with the arrival of digital signal processing (DSP) technology, digital hearing aids also began to emerge. At this point, the majority (90%) of the hearing aids sold in the US are digital, although analog hearing aids continue to be offered because they’re often less expensive, and also because some people have a preference for them.
The way that analog hearing aids operate is that they take sound waves from the microphone in the form of electricity and then amplify the waves, delivering louder versions of the sound waves to the speakers in your ears “as is.” In contrast, digital hearing aids utilize the very same sound waves from the microphone, but before amplifying them they turn them into the binary code of “bits and bytes” that all digital devices use. This digital data can then be manipulated in many complex ways by the micro-chip inside the hearing aid, prior to being transformed back into ordinary analog signals and sent to the speakers.
Both analog and digital hearing aids perform the same function – they take sounds and boost them to enable you to hear better. Both varieties of hearing aids can be programmed by the dispensers of the hearing aids to create the sound quality desired by the user, and to develop settings appropriate for different listening environments. As an example, there might be distinct settings for quiet locations like libraries, for busy restaurants, and for outdoor spaces like sports stadiums.
But beyond programmability, the digital hearing aids generally offer more controls to the user, and have more features because of their capacity to manipulate the sounds in digital form. They have multiple memories in which to store more location-specific settings than analog hearing aids. Other capabilities of digital hearing aids include being able to automatically reduce background noise and remove feedback or whistling, or the ability to prefer the sound of voices over other sounds.
As far as pricing is concerned, 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 advanced features. There is often a perceivable 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.