Figure 1: The sound spectra of three vowels, spoken, analyzed, and recorded by J. Hughes using the program fftscope by H. S. Lu. The vertical dashed lines indicate the corresponding formant frequencies of an ``average'' male voice from Table 15.3 (p. 346) of the textbook The Science of Sound, 3rd Edition, by T. D. Rossing, F. R. Moore, & P. A. Wheeler (RMW).