What is feedback and how can it be used in sound design? Feedback as we know it, is a special kind of positive feedback loop where a sound loop is created between a sound input and a sound output. The classic example is the horrifying and ear piercing screech of a microphone getting too close to a loudspeaker. In this case, the signal received by the microphone is amplified and passed out of the loudspeaker. The sound from the loudspeaker can then be received by the microphone, amplified and passed out the loudspeaker again and again and again creating a feedback loop.