I went through the Matlab tutorial on Formant Estimation using LPC Coefficients. Though I vaguely understand the details, it's not entirely clear why we need to do this. From http://person2.sol.lu.se/SidneyWood/praate/whatform.html:
A formant is a concentration of acoustic energy around a particular frequency in the speech wave
Why is it not enough to take the DFT of the audio signal (after some pre-processing if necessary)? In the frequency-domain, the peaks correspond to these concentrations, correct?