I have a disabled person at home, and I want to make a buser and switch connection for both rooms (More specifically, that I press the button and sound in his room, and that the person press the button and sound in my room) I already made it small with a 9volts battery, a clasp for the battery speaker wire, the buser, but only one sounds and I don't know what it is It would be great if you could help me, thanks and a hug.