To fully understand the difference between analog and digital hearing aids, it is important to first appreciate the history of analog versus digital, and the different ways that they amplify and process sounds. Analog hearing aids came out first, and were the standard in the majority of hearing aids for many years. Then with the introduction of digital signal processing (DSP) technology, digital hearing aids also started to appear. Most (roughly 90%) hearing aids sold 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.
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 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 and computers understand. Once the sound is digitized, the microchip within the hearing aid can process and manipulate the information in complex ways before transforming it back to analog sound and delivering it to your ears.
Analog and digital hearing aids perform the same function – they take sounds and boost them to allow you to hear 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 develop configurations appropriate for different environments. For example, there can be distinct settings for quiet locations like libraries, for noisy restaurants, and for large areas like sports stadiums.
Digital hearing aids, due to their capacity to manipulate the sounds in digital form, generally offer more features and flexibility, and are often user-configurable. For example, digital hearing aids may offer numerous channels and memories, permitting them to store more location-specific profiles. Other features of digital hearing aids include the ability to automatically minimize background noise and remove feedback or whistling, or the ability to prefer the sound of voices over other sounds.
Price-wise, most analog hearing aids continue to be less expensive than digital hearing aids, however, some reduced-feature digital hearing aids fall into the same general price range. Hearing aid wearers do detect a difference in the sound quality produced by analog versus digital hearing aids, but that is largely a matter of personal preference, not a matter of whether analog or digital is “better.”