Some other pages on our site you may enjoy:
ESYNTH - Harmonic analysis/synthesis teaching tool
ESynth is a free program designed to explain the harmonic analysis and synthesis of signals. With ESynth you can create signals by adding together individual sinusoidal waveforms (sinewaves) and study the resulting waveform and spectrum. You can also perform an analysis of an input waveform, to see how a given sound can be represented in terms of a sum of sinewaves. More information.
Web Tutorial on Loudness
A tutorial that provides an extensive introduction to our sensation of the loudness of sounds. More information.