The numbers on the wireless receiver and on the chair are for the wireless network channels. Normally channel will work correctly, but if there is some kind of interference then you can try using a different channel. The numbers stand for different channels. If you have a bad signal, change the number on the chair and also change the number on the wireless transmitter and it will now be sending audio using a different channel.
The wireless channel system works similar works the same kinda way that you tune into a radio station. Station A might be using a frequency of 95.5 and another station might be 105.5. If you want to send a new radio signal you cant use a signal that is already being used. You must use a different signal frequency.