To understand the difference between analog and digital hearing aids, you need to first appreciate the history of analog versus digital, and the different ways that they amplify and process sounds. Analog technology emerged first, and as a result most hearing aids were analog until digital signal processing (DSP) was invented, after which digital hearing aids appeared. At this point, most (90%) of the hearing aids purchased in the United States are digital, although analog hearing aids are still offered because they’re often less expensive, and because some people prefer them.
Analog hearing aids handle incoming sounds by taking the electrical sound waves as they emerge from a microphone and amplifying them “as is” before sending them to the speakers in your ears. Digital hearing aids take the sound waves from the microphone and transform them to digital binary code. This digital data can then be manipulated in many sophisticated ways by the microchip within the hearing aid, before being transformed back into regular analog signals and sent to the speakers.
Analog and digital hearing aids carry out the same work – they take sounds and boost them to enable you to hear better. Both analog and digital hearing aids can be programmable, which means that they contain microchips that can be customized to alter sound quality to match the user, and to create various settings for different listening environments. As an example, there can be distinct settings for low-noise locations like libraries, for busy restaurants, and for large areas such as stadiums.
But beyond programmability, the digital hearing aids often offer more controls to the wearer, and have additional features because of their ability to manipulate the sounds in digital form. For example, digital hearing aids may offer numerous channels and memories, permitting them to store more environment-specific profiles. Other features of digital hearing aids include the ability to automatically reduce background noise and eliminate feedback or whistling, or the ability to prefer the sound of voices over other sounds.
In terms of price, analog hearing aids are in most cases less expensive, although some digital hearing aids are nearing the cost of analog devices by eliminating the more advanced features. There is commonly a noticeable 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.