Science Clip - Sound http://www.bbc.co.uk/schools/scienceclips/ages/9_10/changing_sounds.shtml
The Soundry http://library.thinkquest.org/19537/
Sound http://www.fi.edu/fellows/fellow2/apr99/soundindex.html
Science of Sound http://www.fi.edu/fellows/fellow2/apr99/soundsci.html
Integrated Publishing - Sound Waves http://www.tpub.com/neets/book10/39e.htm
Integrated Publishing - Characteristics of Sound http://www.tpub.com/content/neets/14182/css/14182_31.htm