When trying to fully understand the difference between analog and digital hearing aids, you need to first understand the history of analog versus digital, and the different ways that they amplify and process sounds. Analog hearing aids appeared first, and were the standard in the majority of hearing aids for a long time. Then with the arrival of digital signal processing (DSP) technology, digital hearing aids also started to emerge. The majority of (up to 90%) hearing aids purchased in the US today are digital, although you can still get analog hearing aids because some people prefer them, and they are often cheaper.
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, delivering 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, but before amplifying them they turn the sound waves into the binary code of “bits and bytes” that all digital devices and computers use. This digital information can then be manipulated in many complex ways by the microchip inside the hearing aid, before being converted 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 you can hear them better. Both analog and digital hearing aids can be programmable, meaning that they contain microchips which can be modified to alter sound quality to suit the user, and to create various configurations for different listening environments. As an example, there can be different settings for low-noise locations like libraries, for busy restaurants, and for large areas such as stadiums.
Digital hearing aids, because of their capacity to manipulate the sounds in digital form, often offer more features and flexibility, and are often user-configurable. They have an array of memories in which to store more location-specific configurations than analog hearing aids. They can also use advanced rules to identify and minimize background noise, to eliminate feedback and whistling, or to selectively detect the sound of human voices and “follow” them using directional microphones.
In terms of price, analog hearing aids are in most cases cheaper, although some digital hearing aids are approaching the cost of analog devices by removing the more advanced features. There is commonly a noticable difference in sound quality, but the question of whether analog or digital is “better” is entirely up to the wearer, and the ways that they are used .