That will be a relay in the unit.. HOWEVER.. I highly recommend running on high all the time.... Two reasons.
1: This helps with moisture control and de-icing of the evaporator (Cold) coils
2: The steady drone of that fan covers a lot of other noise,, Like the couple across the road having a knock down/drag out.. Or the police radios as they loaded him and her into different cars for transport, or.. Well you get the idea (NOTE: That was not made up, happened last week right across the drive)
Home is where I park it!