I could see a number of neat sound options:
Harley Davidson Motorcycle
Ride of the Valkyries
Star Wars Theme
Theme from Jaws (both fun and a great warning!)
In reverse - the standard Beep, Beep, Beep that we all know and hate (but it gets your attention).
As we unveil EE Times’ 2015 Silicon 60 list, journalist & Silicon 60 researcher Peter Clarke hosts a conversation on startups in the electronics industry. Panelists Dan Armbrust (investment firm Silicon Catalyst), Andrew Kau (venture capital firm Walden International), and Stan Boland (successful serial entrepreneur, former CEO of Neul, Icera) join in the live debate.