A little bit of history and an explanation of how analog devices work vs 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, after which digital hearing aids appeared. Currently, most (90%) of the hearing aids purchased in the United States are digital, although analog hearing aids continue to be sold because they are often lower priced, and because some people prefer 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, sending louder versions of the sound waves to the speakers in your ears “as is.” In contrast, digital hearing aids utilize the same sound waves from the microphone, however before amplifying them they turn the sound waves into the binary code of ones and zeros that all digital devices use. This digital data can then be altered in numerous sophisticated ways by the micro-chip within the hearing aid, before being transformed back into regular analog signals and delivered to the speakers.
Remember that analog and digital hearing aids have the same function – they take sounds and boost them so that you can hear them more easily. Both analog and digital hearing aids can be programmable, meaning that they contain microchips which can be modified to adjust sound quality to match the user, and to create various configurations for different environments. For example, there can be different settings for quiet locations like libraries, for noisy restaurants, and for outdoor spaces like sports stadiums.
But beyond programmability, the digital hearing aids often offer more controls to the wearer, and offer more features because of their ability to manipulate the sounds in digital form. They have multiple memories in which to save more location-specific settings than analog hearing aids. They can also employ sophisticated rules to detect and reduce background noise, to remove feedback and whistling, or to selectively detect the sound of voices and “follow” them using directional microphones.
In terms of price, analog hearing aids are generally cheaper, although some digital hearing aids are nearing the cost of analog devices by eliminating the more advanced features. There is often a perceivable difference in sound quality, but the question of whether analog or digital is “better” is up to the wearer, and the ways that they are used.