Hi Boomer!
Well, that would be annoying and it is a strange thing.
Do you have the speakers plugged into the correct audio port in the computer or is this coming from a laptop?
For a quick fix, turn the computer OFF at night or at least turn off the power to the speakers.
My speakers have a power knob as well as a separate volume control and bass and treble controls.
Let me know what your situation is and we'll try to get it figured out for you!
the best,
micro...