You can hear the windows XP message box sound right before that. Which surprises in two ways: a) they're still using windows XP (ok well we still do too at work for some appliance from the power company). b) it seems you're not hooked into the machine via some modem or virtual-something over lan, but something that connects to the sound card, otherwise I've no idea how system sounds that always play on the default card would end up in the phone call. That means there's one machine handling one call at a time.