A bit of background and an explanation of how analog devices work versus how digital devices work is essential to understand the distinctions between analog and digital hearing aids. Analog technology emerged first, and consequently most hearing aids were analog until digital signal processing (DSP) was invented, at which point digital hearing aids appeared. At the moment, most (90%) of the hearing aids sold in the United States 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 work is that they take sound waves from the microphone in the form of electricity and then amplify the waves, sending louder versions of the sound waves to the speakers in your ears “as is.” In contrast, digital hearing aids take the very 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. This digital data can then be manipulated in numerous complex ways by the micro-chip within the hearing aid, prior to being converted back into regular analog signals and delivered to the speakers.
Remember that both analog and digital hearing aids have the same function – they take sounds and boost them so you can hear them 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 individual user, and to create various settings for different environments. For example, there might be distinct settings for quiet locations like libraries, for busy restaurants, and for outdoor spaces like stadiums.
But beyond programmability, the digital hearing aids often offer more controls to the user, and have more features because of their capacity to manipulate the sounds in digital form. For example, digital hearing aids may offer multiple channels and memories, permitting them to save more environment-specific profiles. 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 human voices over other sounds.
Price-wise, most analog hearing aids are still less expensive than digital hearing aids, but some reduced-feature digital hearing aids are now in a similar 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.