Automatic measurement of vowel formants using Praat and R

This tutorial will cover how to automatically measure formant values, the method proposed in Escudero et al. (2009). This method measures formant values (both F1 and F2) 201 times by varying the setting for the formant ceiling value from 4500 Hz to 6500 Hz and finds the formant ceiling that shows the lowest variance in measured F1-F2 pairs. This tutorial will cover how to measure vowel formants with a for loop in Praat (measuring F1 and F2), find the lowest variance per speaker, and plot vowel spaces in R (finding the formant ceiling with the lowest variance). 

Ref: Escudero, Boersma, Rauber, and Bion. 2009.  A cross-dialect acoustic description of vowels: Brazilian and European Portuguese. Journal of Acoustical Society of America, 126(3), 1379-1393.