The science of sound

Don't be put off by the title, it's not too technical.

<object width="640" height="510"><param name="movie" value="http://www.youtube-nocookie.com/v/i_0DXxNeaQ0?version=3&amp;hl=en_GB"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube-nocookie.com/v/i_0DXxNeaQ0?version=3&amp;hl=en_GB" type="application/x-shockwave-flash" width="640" height="510" allowscriptaccess="always" allowfullscreen="true"></embed></object>