In an open public wlan anyone can listen to your network traffic. This is what it might sound like.
I did this by hooking up Processing with Wireshark to provide visualization and soundalization of the sniffed network traffic, and then connected to a freely available public wlan to sniff packets flying around me. It is a very hypnotizing real time experience to actually hear the ongoing network traffic!
For real time performance the packet counts were aggregated by protocol type, and a sound was played when the packet count for a protocol exceeded a threshold level.
Made with Processing and Wireshark.