Simply put, analog hearing aids are the most basic type of hearing aids – they simply amplify all sounds equally.
They do not account for whether the sound is speech or noise and disregarding whether it might already be a very loud sound. In analog devices, there is a limit on the number of criteria that can be controlled, so there is in-turn a limitation on fine-tuning the sound being delivered to the consumer.
The onset of digital sound processing technology has since changed how the above-mentioned process is carried out. Microchips present in the digital device convert sound waves to binary code (the language of computers) and applies certain algorithms (mathematical formulae) so as to reduce noise, improve the sound quality of spoken voice, reduce feedback of device (often producing an annoying whistling sound) and perform complex sound processing.
This processed sound is then played back to the ear, thus giving the user a comfortable hearing solution minus the noise and other distractions.