This video gives the essentials of how a hearing aid functions.
Two microphones work together to pick up sounds from the environment. The sound is transmitted through an analog-digital converter or ADC which converts analog sound into an electronic signal. Computer chips then process this digital sound. This is pretty advanced!
Computer chips can be adjusted to suit the individual’s hearing. Some people may be able to hear low frequencies with ease but others only detect higher frequency. A few people can detect low frequencies very well, whereas others cannot. There are many more who fall in between. Hearing aids have to be high-tech to help the people who have various hearing impairments.
If you’re thinking it’s a long process. The process takes only a millisecond or so to complete the procedure. There will be no lag between sounds that surround the wearer, and those sent to them by the hearing aid.
You can find more details in the video below.