Talk:Staff List/@comment-8440302-20131231141422/@comment-24780238-20140406000128

If there was no noise and it became cold, then that is what's called an endothermic reaction. Meaning that your hand took the heat energy from the can, which would make the can cold, this also explains the noise. You see an air horn requires air pressure to operate, and for there to be pressure the gas inside would have to be at a certain temperature range, if it becomes colder the gas molecules will gather closer together as it nears it's liquid state of matter.