To give you an idea of what this innovation may look like on completion here is a glimpse of what has influenced the thought process.
First off we have the hamster exercise ball.
(Attribution http://www.flickr.com/photos/striatic/3258609/ )
And secondly by the Zorb which, if you have not encountered one before is an inflatable human adult sized version of the hamster ball.
(Attribution http://www.flickr.com/photos/gak/131650182/in/photostream/ )
You may see where Polybore is going with this. Not sure how the sound proofing is going to work though, all suggestions gratefully received.