The first problem may seem insignificant, but it can actually get very annoying. This is because the sound setup on my computer is somewhat finicky, having batteries that can wear out means there is one more thing to check when my sound stops working.
Poor transmitting range is more common and much more annoying. In general wireless headphones work fine if you are sitting three feet from the transmitter. But if you are like me you like to do things while you are using your headphones. Most cheap wireless headphones carry five to ten feet. In my case I wanted mine to carry farther than this, so I added an extra antenna.
So now that you know what we are going to do why don't you go to the next step to see what materials and tools you will need.
Doing this instructable may conflict with your local communications authorities rules the legality of this is entirely your responsibility.