I'm trying to figure out a way to have computer wav files be able to play as the input on a phone. My brother mentioned something that one of his friends used to have. He says it was a box that you connected to a sound card and then connected the phone to the box. This would then allow any sound played on the computer to go directly as the input to the phone. Problem is, he didn't remember what it was called, only that it cost about $20-$30. Anyone have any idea what something like this might be called?