Your hearing aids have internal microphones, which are what they use to pick up environmental sound and amplify it. However for severe hearing losses or very noisy situations, sometimes placing a microphone closer to the person speaking is the best solution to reduce noise and hear speech clearly.
Remote microphones can be useful in the car, or in public places like museums or busy restaurants where you need to hear someone more clearly. All major hearing aid manufacturers offer microphone accessories to provide an additional boost in a variety of situations. Some may sit on a table to enhance the sound of audio in a meeting, while others may be handheld to allow friends and loved ones to easily pass them around to make sure you don’t miss a word. While not everyone may need to make use of external microphones, they can be important tools for some situations.