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 alternative ways that they amplify and process sounds. 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. At this point, the majority (90%) of the hearing aids purchased in the US are digital, although analog hearing aids are still offered because they’re often lower priced, 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 them, sending louder versions of the sound waves to the speakers in your ears “as is.” On the other hand, digital hearing aids take the same sound waves from the microphone, however before amplifying them they turn them into the binary code of ones and zeros that all digital devices and computers use. This digital data can then be manipulated in numerous sophisticated ways by the micro-chip inside the hearing aid, prior to being converted back into regular analog signals and sent to the speakers.
Analog and digital hearing aids perform the same work – they take sounds and amplify them to allow 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 configurations ideal for different listening environments. As an example, there can be distinct settings for low-noise rooms like libraries, for noisy restaurants, and for large areas like stadiums.
But beyond programmability, the digital hearing aids generally offer more controls to the wearer, and offer additional features because of their capacity to manipulate the sounds in digital form. For example, digital hearing aids may offer numerous channels and memories, permitting them to save more location-specific profiles. They can also employ advanced algorithms to detect and minimize background noise, to remove feedback and whistling, or to selectively prefer the sound of voices and “follow” them using directional microphones.
In terms of price, analog hearing aids are generally less expensive, although some digital hearing aids are approaching the price of analog devices by eliminating the more sophisticated features. Hearing aid wearers do notice a difference in the sound quality produced by analog versus digital hearing aids, but that is largely a matter of preference, not really a matter of whether analog or digital is “better.”