We received a complaint that our hold music is way too loud.
Apparently a deafening blast of Blondie, "hanging on the telephone". The poor chap jumped because it was too loud, and managed to hit is head somehow.
Obviously not happy.
But there is a slight catch.
We don't have any hold music!
What we have at the office is a quiet comforting "beep beep" every 3 seconds. Certainly no Blondie!
But the phone system passes the "on hold" signal through SIP. It even finds its way out through the PSTN, ISDN and even mobile systems in some cases. So you get "on hold" on the screen of your phone even. This is not always the case, some types of interconnect lose the signal, but in many cases this gets all the way to the far end phone system.
What this means is that the music on hold this person heard was his own phone system's hold music.