Dave,

If you mean the whirring of the DVR's hard drive, no, that never shuts off when you turn off the DVR, only if you unplugged the unit.

If it's a ground-loop hum you are hearing through the speakers or subwoofer or the TV's speakers which is caused by the cable-TV input, that too will continue whether the DVR is on or off. That would disappear if you turned off the TV, subwoofer or AV receiver, which amplify the ground-loop.

Regards,

Alan

Alan Lofft,
Axiom Resident Expert (Retired)