There is no female vocal tract:
Abandoning essentialist ideology inphonetics
Santiago Barreda
University of California, Davissbarreda@ucdavis.edu

Michael Stuart
National Yang Ming Chiao Tung University
1

Vowel Formant DataMaleFemale2Fant (1966) - A note on vocal tract size factors and nonuniform F-pattern scalings“The female to male scale factor is of the order of18% averaged over the whole vowel system.
The typical deviations from this rule are:[…](c) Very open front or back vowels display a firstformant “sex factor” k1 which is substantiallyhigher than the average.
[…]
These findings conform with anatomical
constraints of the average female vocal tract. The
particular scaling from male to female tract
reduces the pharynx length more than the lengthof the mouth.”æ3

Fant (1966) - A note on vocal tract size factors and nonuniform F-pattern scalings●

Q: Why is the female vowel space adifferent shape than the male vowel
spaces?
æ●

A: Because of the constraints of thefemale body.

4Non-uniform scaling = Phonetically salient
Frontness

Heightæ

ææ

5

Fant (1966) - A note on vocal tract size factors and nonuniform F-pattern scalings●

Q: Why is the female vowel system
phonetically different from the malesystem?
æ●A: Women produce these linguistic
differences because of theconstraints of the female body.
6Sex and Gender●

Sex: Categories based on anatomy/physiology.

●

Gender: Categories based on cultural/social practices.

●

Both are socially constructed and are historically contingent.
e.g., conceptions of ‘biological’ sex 100 years ago did notinclude hormones (Sans 2017).
○7

Opposing View on Sex and Gender1.

Essentialist:○Direct link between anatomy/physiology gender (sex == gender).
○ “Women speak in a feminine manner because it is inherent to theirfemale bodies”.
2.

Constructivist:○No deterministic link between gendered speech and female bodies(sex != gender).
○ “To the extent that women produce ‘feminine’ speech, it is due tosocialization and culture”.
8Fant (1966): Essentialist ideology
The framing and conclusions conveys
the following perspective:
1.

Discrete, easily separable male andfemale anatomical differences.
?

9Fant (1966): Essentialist ideology
The framing and conclusions conveys
the following perspective:
1.

Discrete, easily separable male andfemale anatomical differences.

2.

Males set the standard; women try
to copy it.

æ10Fant (1966): Essentialist ideology
The framing and conclusions conveys
the following perspective:
1.

Discrete, easily separable male andfemale anatomical differences.

2.

Males set the standard; women try
to copy it.

3.

The female copy fails because of‘constrained’ female body.

æ11

Main Arguments

1) There are no necessary differences in vocal tract anatomy between

male and female speakers.
2) The anatomical differences between male and female speakers are

not causally related to the linguistic properties of male and female
speech.
3) Let’s update how we think about normalization, from “removinganatomical variation” to “representing phonetic variation”.

12Part 1: There are no necessary differences invocal tract anatomy between male and female
speakers.

13

Fant (1966) - A note on vocal tract size factors and nonuniform F-pattern scalings●“The main physiological determinant of the specific deviations from theaverage rule is that the ratio of pharynx length to mouth cavity length isgreater for males than for females and that the laryngeal cavities are moredeveloped in males.” (p. 22)

Male Pharyngeal Cavity Length Female Pharyngeal Cavity Length>
Male Oral Cavity Length
Female Oral Cavity Length
Male P/O > Female P/O

Simplified: Men have proportionally smaller
heads (or longer necks) than women.
14VTL ~ height

FemaleMaleAvg.
Male

Turner et al. (2009)
Fitch and Geidd (1999)

Avg.
Female15

VT Cavities ~ height

Avg.
FemaleFemale
MaleAvg.
MaleOral cavity/VTL

Pharyngeal cavity/VTLTaller

Turner et al. 2009
Fitch and Geidd 1999

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Head ~ heightTaller

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Height, not sex!

FemaleMale

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Part 2: Anatomical differences between females andmales are not causally related to the phonetic
properties of gendered speech.

19

Gendered Differences = Phonetically salient
FrontnessHeightæ
æ

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Gendered Dialect“male/female vowel formant differences arevariable across languages and dialects of thesame language. […] these data suggest thatgender differences are not solely due to vocal
tract anatomical differences between men
and women”“the overall conclusion is clear. People(perhaps especially men) perform gender.”Johnson (2006), p. 487
21

Gendered DialectFrontness

Not denying the existence ofgendered linguistic differences.

●Denying the necessaryconnection of linguistic variation
to anatomical differences between
men and women.

Height●ææ

22

Inviolable principle: Linguistic Universality●

Any human that can reach fullcompetence in language X could’ve
reached full competence in language Y.

●Alternate version: The language faculty isnot language-specific.

23Linguistic Universality: Gendered Variation
Since any speaker can potentially reach fullcompetence in any L1…..
Could women learn a language that is justlike the male targets (i.e., with a slightlyhigher /æ/)?
○○FemaleFrontness

Height●Male (“target”)

No: Women can’t be native speakers ofat least some languages.
Yes: Gendered phonetic variation
should not be dismissed as ‘anatomical’.
24Phonetic vs. Acoustic●Vowel sounds have a dual reality:1.

2.

●

Physical acoustic characteristics(measured in dB and Hz).

Linguistic/phonetic properties, there
consistent of vowel quality, height andfrontness.

(1)

(2)

Human bodies can limit (1) but not (2).
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Linguistic Universality: Gendered Variation●Can these female speakers produce thedashed blue system?

●

The answer is obviously yes.
æ●The gendered difference should not be
attributed to “anatomy”.

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“Anatomical” Variation: A red herring• “[A]s is well known, an infinite number of shapes of different
lengths are realizable for a given set of formant frequencies andbandwidths” (Wakita 1977, p. 190).
• The bodies of identical twins can produce substantially different
formant patterns for the ‘same’ vowels (Zuo & Mok 2015).
• Conclusion: A single human body can produce arbitrarily
different formant patterns, and an infinite number of anatomies
and gestures can be combined to yield any given formantpattern.

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Part 3: Let’s update how we think aboutnormalization, from “removing anatomicalvariation” to “representing phonetic variation”.

28Vowel Normalization Algorithms• Map from an acoustic representation to a phonetic/linguisticrepresentation.
𝑓 F1 , F2 , F3 = N1 , N2 , N3
F2N1 (Frontness)

f(x)

uɛ

ʌæ

N2 (Height)

F1iɑ

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Choosing Normalization Algorithms

Log-meanLobanov

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Variation in F1

What causes an observed F1 frequency?

Essentialist:
F1 = Sex + Phoneme(where sex==gender)

Constructivist:
F1 = Sex + Phoneme(where sex!=gender)
F1 = (Body + Gender) + Phoneme

31Normalizing variation in F1
What if we can successfully erase (non-phonetic) body differences?
●Essentialist view: Only phoneme information remains.

F1 = Sex + Phoneme
N1 = Sex + Phoneme●(where sex==gender)

Constructivist view: Phoneme and gender information remains.

F1 = Body + Gender + Phoneme
N1 = Body + Gender + Phoneme32Adank et al., (2004): Erasing gender• Evaluated normalization methods (in part) on their ability to erase gender
information.
• “a procedure is successful at eliminating gender-related anatomical/physiologicalvariation when [the LDAs are] performing at chance level” (p. 3103).
Gender ~ NF1
Essentialist expectation: Impossible to predict gender.
NF1 = Sex + Phoneme
Sex/Gender ~ Sex + Phoneme
Constructivist expectation: Possible to predict gender.
NF1 = Body + Gender + Phoneme
Gender ~ Body + Gender + Phoneme

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Voeten et al. (2022) : Erasing individual variation• “There are two goals to speaker normalization: retaining (socio)linguistic
information (here, vowel identity and regional origin) and normalizing
anatomical differences (here, speaker sex and individual differences between
speakers matched on sex, age, and region).”• “We consider a normalization method to perform well if it maintains differences
between vowels and regions, normalizes differences between the two speakersexes, and similarly normalizes individual speaker differences.” Voeten et al.
(2022)
F1 = Phoneme + Dialect + Sex + Individual differences
NF1 = Phoneme + Dialect + Sex + Individual differences
NF1 = Phoneme + Dialect + Sex + (Gender + SF1 + SF2 + … + SFN)
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How did we get here?

1. Early on, a focus was placed on anatomical variation between
men and women.

2. ‘Anatomy’ was identified as the source of differences between
men and women.
3. ‘Anatomy’ was extended to generally explain much betweenspeaker variation.
4. This has led to wide-scale overnormalization of linguistic data.

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Overnormalization• Overnormalization: The erasure of legitimate phonetic and social
information from our data.
NF1 = Phoneme + Body + Gender + SF1 + SF2 + … + SFN
Log-mean

NF1 = Phoneme + Body + Gender + SF1 + SF2 + … + SFN
Lobanov

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Begging the question: Gender variation• Begging the question of a lack of gender differences:
1. We collect data to see if men and women are different

2. We normalize, using a method selected because it makes men and women as
indistinguishable as possible.
3. We then test for a difference between men and women, finding none.
4. We report that there is no difference between male and female speech (apartfrom the ‘anatomical’ differences we erased of course).

5. Future researchers continue with the assumption that there are nomale/female differences apart from those related to anatomy.
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Reproducing ideologies• Eckert (2014): “the gender binary is maintained by the continued ‘doing’ ofgender – every time a person uses a single-sex restroom, he or she isreproducing that binary” (p. 529).
• When we normalize with the intention of removing gender differences inspeech because they are ‘anatomical’, we reproduce essentialist gender
ideology unintentionally.
Log-meanLobanov

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The way forward: Focus on phonetics• Overnormalization is akin to overfitting: Removing ‘too much’ variation.
• Without a phonetic (not phonemic) ‘ground’ truth, this is bound to happen.
• The only way to avoid overnormalization: Focus on preserving phonetic
information, erase only non-phonetic acoustic variation.
• Forget trying to infer the cause of variation:• Focus on erasing non-phonetic variation, regardless of the source.
• Focus on representing phonetic variation, regardless of the source.
39Thank you!!

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References
Eckert, Penelope. "The problem with binaries: Coding for gender and sexuality." Language and Linguistics Compass 8.11 (2014): 529-535.
Fant, G. (1966). A note on vocal tract size factors and non-uniform F-pattern scalings. Speech Transmission Laboratory Quarterly
Progress and Status Report, 1, 22-30.
Fitch, W. T., & Giedd, J. (1999). Morphology and development of the human vocal tract: A study using magnetic resonance imaging. The
Journal of the Acoustical Society of America, 106(3), 1511-1522.

Turner, R. E., Walters, T. C., Monaghan, J. J., & Patterson, R. D. (2009). A statistical, formant-pattern model for segregating vowel typeand vocal-tract length in developmental formant data. The Journal of the Acoustical Society of America, 125(4), 2374-2386.

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