Formants are standing-wave resonances of the vocal tract itself

Evidence

When considering the acoustics of speech and singing, the standing wave modes are generally referred to as “formants.” Idealized frequency response curves for a vocal tract set to produce the vowels in the words fast, feed and food are shown in Figure 4.35 and the center frequency of each formant is labeled starting with “F1” or “first formant” for the peak that is lowest in frequency, continuing with “F2” (second formant) and “F3” (third for­ mant) as shown in the figure. The formants are acoustic resonances of the vocal tract itself resulting from the various dimensions of the vocal tract spaces. — David Howard, Jamie Angus, coustics and Psychoacoustics, 1355

When considering the acoustics of speech and singing, the standing wave modes are generally referred to as “formants.” Idealized frequency response curves for a vocal tract set to produce the vowels in the words fast, feed and food are shown in Figure 4.37, and the center frequency of each formant is labeled starting with “F1” or “first formant” for the peak that is lowest in frequency, continuing with “F2” (second formant) and “F3” (third formant), as shown in the figure. The formants are acoustic resonances of the vocal tract itself resulting from the various dimensions of the vocal tract spaces. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1345

Categorization

• DEFINE: Establishes the core definition: formants = vocal tract standing wave modes, distinct from the source pitch.
• corroborated: 2 independent passages support this claim — David Howard, Jamie Angus, coustics and Psychoacoustics, 1355; David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1345