So, it follows that a speeded up recording of humans would sound like birds ? This is a very interesting piece of research and has quite possibly changed my life for ever.Leonard Pinkethinge
Interestingly, Mr Pinkethinge, your surname is the Anglicized version of the Dutch "ponke thonge", meaning "pink thing"
Go on... you want to say SOMETHING, don't you? Post under a made-up name if you're shy!