Answer:
1.
information about reactions to a product, a person's performance of a task, etc. which is used as a basis for improvement.
"throughout this process we have obtained valuable feedback"
2.
a screeching or humming sound resulting from the return of a fraction of the output signal from an amplifier, microphone, or other device to the input of the same device.
"Punk Rock Girl opens the disc with plenty of guitar feedback"
