TO PIPE = to transport via pipes
PIPED MUSIC is not transported by pipes but it is sent via wires and loudspeakers from the sender to the listener. Possibly the expression came from "piping" (blowing a small metal pipe or whistle) to communicate sounds on a ship. The advantage of a pipe/whistle is that a command can be transmitted, heard, understood and obeyed even during a loud storm. Today "piping" mainly ceremonial, an old tradition. When music is piped to us, we have no control over it.
I do not know, nor do I want to know, who wrote the sentence below, but he was not a native speaker. Do not use what he wrote as an example of the use of "piped".
"I agree, every moment during our day involuntary we hear aggressive noises. For instances, at the bus there is always someone listening a piped music without hear phone, ..."