They do not invite dogs to the American Association for the Advancement of Science (AAAS) annual expo - which is a good thing.

The animals would be howling if they heard the collection of new musical instruments that have just been presented to the conference. That is unfair, of course - but these instruments made some very unusual noises. Click on the audio icon and see what you think.

Susan Rawcliffe: It is about freedom

You might take the view that modern synthesisers can create virtually any noise but these musicians say computers do not really give them the freedom they seek.

Susan Rawcliffe makes and plays ceramic flutes and whistles in a wonderful array of shapes derived, in part, from Precolumbian models. She says synthesisers are too predictable:

"If you take a sound and sample it and put it on a synthesiser all you would get is that little clip over and over again, with no variation - every time I do it, it's different."

Odd shape, odd sound

Bart Hopkin, a designer, builder and long-time student of acoustic musical instruments agrees. He says novel instruments are about the joy of exploration.

"To me what is most interesting about new instruments is that they will take you to places, sound-wise, that you wouldn't have thought of if you hadn't had the instrument.

"If you take a classical instrument and approach it with the idea that you want to become master of the instrument, you've defined a set of parameters.

"If you take a new instrument, which you've never approached before, you're not going to be master of it, so you'd better just see where it wants to go - and where it wants to go might be somewhere you'd never have thought of going."