F0 and formants

[Qianchu L]

I am a bit confused about:

1. Will vocal tract affect F0? You said that people sound ‘big’ (I guess it means lower pitch?) because they have longer vocal tract. But as F0 is a property of the source in the glottal pressure wave, how can vocal tract affect F0?

2. Is it correct to think that :
(1)female-male pitch difference is mainly caused by the fact that men have longer vocal folds?
(2) female speakers generally have slightly higher formants in vowels because they have shorter vocal tract than men?

[Simon]

Vocal tract length

On average, men have slightly longer vocal tracts than women, and so the formants in male speech will be a little lower than in female speech.

Fundamental frequency

Generally, male speech has a lower fundamental frequency (F0). This is due to a combination of anatomical differences, both in the vocal folds themselves and the larynx. This article seems to summarise the factors quite well.

[Yichao L]

Following the reply above, why can’t/don’t they reshape their vocal track and adjust their F0 so that the speech they produce has the same formants?

Besides, how much lower is “a little lower” as in “the formants in male speech will be a little lower than in female speech”?

[Simon]

It’s vocal tract, not “vocal track”.

Vocal tract length is determined mainly by anatomy; speakers can only vary it a little (e.g., by protruding the lips)

Likewise, a speaker’s F0 range is determined by anatomy and can only be varied within that range.

F0 and formants are independent things, so “adjust their F0 so that the speech they produce has the same formants” is incorrect.

[Yichao L]

Then why does a longer vocal tract results in lower formants instead of higher formants.

[Simon]

Longer tubes have lower resonant frequencies than shorter tubes.

[Author]

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