Widely spaced harmonics smear or hide formant peaks in high notes

Evidence

In this example, there are three formant peaks shown, and it can be seen that in the cases of the lower two notes, the formant structure can be readily seen in the output but that in the case of the highest note, the formant peaks cannot be identified in the output spectrum because the harmonics of the input are too far apart to represent clearly the formant structure. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1354

Categorization

• XREF: Connects to the soprano/formant-tuning passage right after it, and to generic source-filter model of speech.