For man, the perfectly pure and mathematically defined sound exists as a theoretical concept only. The French mathematician Fourier knew and stated this when he was developing his theory of harmonic analysis. Distortion results the moment a sound is produced, for the sounding object first has to overcome its own inertia to be set in motion, and in doing this little imperfections creep into the transmitted sound.

Schafer, Murray R, The Soundscape- Our Sonic E…, loc. 880