LPC and Physics

Subtractive synthesis uses a complex source wave—such as an impulse, a periodic train of impulses, or white noise—to excite a spectral-shaping filter. Linear prediction, or linear predictive coding (LPC), gives us a mathematical technique for automatically decomposing a sound into a source and a filter. For low order LPC (6-20 poles or so), the filter is fit to the coarse spectral 

Rabiner. Digital Formant S5mthesizer. Journal of the Acoustical Society of America 43(4) 822-828 (1968). 

Market and A. Gray. Linear Prediction of Speech. New York Springer, 1976. 

---