Do you have a question about the Sony MDR-IF5000 and is the answer not in the manual?
Locate and open the battery compartment lid on the top of the left housing.
Insert two R6 (size AA) batteries into the compartment correctly.
Close the battery compartment lid securely after inserting batteries.
Ensure the connected audio/video equipment is powered on before proceeding.
Power on the infrared transmitter or Digital Surround Processor unit.
Wear the headphones; power turns on automatically and indicator glows red.