Vowels and speech production: gender differences

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Vowels and speech production gender differences

• Presentation from Lina Hecker
• Speaker Characteristics
• Venice International University
• Prof. Dr. Jonathan Harrington
• 17. October 2007

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Introduction

• there have been some analyses of female speech in
  the past
• ? focal point has been the male voice
• female voice has a higher frequency range
• men are more studied and they are regarded as the
  standard to which everything else is compared
• in this lecture you can hear some differences in
  the speech of females and males based on adults
• focus on dynamic articulatory and acoustic
  consequences of differences in male and female
  vocal tract dimensions
• and the relationship between formant change and
  tongue movement

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1. What are the dynamic articulatory and acoustic
consequences of differences in male and female
vocal tract dimensions?(Simpson 2001)

• Simply illustrated in Goldstein (1980) using the
  mid-sagittal vocal tract dimensions
• models vocal tract growth from infant to adult
  and its acoustic products
• Goldstein draws together available anatomical
  dimension data from a number of qualitative and
  quantitative different sources

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Conclusion of Figure 1

• In the figure female stricture sizes are
  calculated as 80 of the male values.
• It shows superimposed tongue positions for female
  (solid) and male (dashed) i and a.
• The distance from male a to i is 11 greater
  than the analogous female distance.
• If you assume the same nominal articulatory speed
  and neglect inertia and acceleration, then the
  male VV movement will also take 11 longer.

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2. The relationship between the size of oral
structures and its implications forarticulatory
displacement and articulatory velocity.(Kuehn
Moll 1976)

• They showed that the subjects with larger oral
  structures, had larger articulatory displacement
  and employed greater articulatory velocity to
  traverse larger articulatory spaces.
• ? focused on the general consequences of
  differences in oral structure size
• ? did not discuss the more wide-ranging
  implications of their findings for gender
  specific consequences in articulatory behavior
  and its acoustic products

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• Explanation of Figure 2
• In the next figure you can see a hypothetical
  male and female F1 paths for openclose vowel
  movement, assuming the same nominal tongue body
  movement speed of 200mm/s.
• ? the male acoustic trajectory lasts longer
  than the female one
• ? the linear acoustic rate of change of F1
  for females is 35 greater than the male
  value.
• gt female tongue covers a shorter distance
  to achieve analogous targets, and
  corresponds to a greater acoustic distance.

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• Conclusion of Figure 2
• males and females aim for analogous phonetic
  vowel targets in CVC sequences
• if they move their articulators at the same
  speed, and if they are operating within the same
  durational framework
• ? females reach their target earlier
• female degree of openness is greater than the
  male one
• females exhibit less undershoot than males
• ? undershoot increases from close to open vowel
  categories
• gt despite dimensional differences, targets are
  attained at approximately the same time with a
  difference in articulatory speed

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3. The Relationship between formant change and
tongue movement

• main articulatory-acoustic patterns found in
  diphthongs (Simpson 2001)
• average male and female pellet and formant tracks
  are similar in form
• female speakers cover a greater acoustic space
  both in linear (Hz) and nonlinear (Bark) terms
• The articulatory distance covered by the two
  posterior lingual pellets during the vocalic
  stretch is greater for male speakers
• the dorso-tectal stricture size defined by the
  two posterior lingual pellets is smaller for
  female speakers throughout the vocalic stretch
• mean pellet speeds are greater for male than
  female speakers

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3.1. Data UW-XRMBDB (Westbury, 1994)

• data set for examining gender-specific
  differences in the relationship between
  articulation and its acoustic products
• contains acoustic and articulatory records from
  26 female and 22 male speakers (age 18-37),
  speaking Upper Midwest dialect of Am. English
• linguistic (e.g. reading text) and non-linguistic
  (e.g. swallowing) tasks
• articulatory data consists of 8 gold pellets
• 4 lingual pellets are placed along the midline of
  the tongue

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3.2. Method

• use stretches of utterance to investigate the
  dynamic relationship between acoustic and
  articulatory activity which fulfill 3 criteria
• large amounts of articulatory and acoustic
  movement
• continuous voicing throughout the stretch to
  facilitate reliable automatic formant tracking
• repetition by the same speaker of the same
  expression containing a suitable stretch.
• The coat has a blend of both light and
  dark fibers.
• They all know what I said

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A Formant analysis

• analysis of the vocalic stretch of they all
  made with the ESPS program formant
• nominal default value of F1 was increased by 10
  to 550Hz for female speakers
• analysis times were extended by 25ms beyond the
  segment start and end times
• formant tracks of the 239 tokens were visually
  checked for tracking errors
• each set of formant tracks was resampled to
  provide 11 temporally equidistant formant
  records
• 11 points provide a good definition of formant
  movement throughout the vocalic stretch

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B Pellet position

• pellet position of the UW-XRMBDB are stated in a
  coordinate system
• The normalization method redefines the position
  of the pellets on the tongue surface, with
  respect to their distance from the tip of the
  upper incisors.
• normalization allows to compare values from
  speakers with different palate outline lengths
• raw pellet positions were averaged separately for
  males and females
• male and female average palate outlines were
  created using individual palate outlines,
  resampled at 0,5mm intervals

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3.3. Results

• 3.3.1. Duration
• a one-tailed t-test for the V-V stretches shows
  that the mean female duration is greater than the
  male one
• ? no significant difference was found between the
  male and female durations of the utterances
• in other studies there were also found longer
  female durations for diphthongs (Simpson 2001)
  and monophthongs (Hillenbrand, Getty, Clark
  Wheeler 1995)

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• 3.3.2. Formant tracks
• at the 11 equidistant measurement points means
  and standard deviations of F1-F3 were calculated
  for males (right) and females (left) tokens.
  (next fig)
• formant values for the V-V stretch for they all
  can only cautiously compared with the results
  found in the literature
• speakers in the UW-XRMBDB speak an Upper Midwest
  American English
• vowels are from the initial part of the
  utterance,
• particularly they being utterance-initial,
  unstressed and preceding a stressed back open
  vowel ? expect a more centralized vowel than you
  would find in isolation or utterance finally

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• In the next figure you can see a graphical
  comparison of the mean male and female formant
  tracks, converted to the Bark scale.
• In linear (Hz) terms, female acoustic excursion
  within the vocalic stretch is greater for both F1
  and F2
• In non-linear (Bark) terms, situation is
  different. The mean tracks for F2 and F3 run
  parallel with little change and a distance
  between them throughout the vocalic stretch.
• difference in mean F1 is 0,74 Bark at the
  beginning and is 1,58 Bark (more than twice) by
  the end of the stretch
• ? suggesting a closer male vowel or a more open
  female quality
• ? more open the vowel quality, the larger the
  difference becomes between female and male F1

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• Explanation of figure 5
• during vocalic stretch tongue body makes a small
  upward moving before moving backwards and
  downwards
• F1 is determined by the apico-dental stricture of
  they over the initial part of the stretch
  (t1-t4)
• at the final part of the stretch (t5-t11) the
  tongue body is lowered, resulting in an increase
  in the size of the dorso-palatal stricture
  defined by T2T4
• F2 rises (t2-t4) to reach a plateau at (t3-t4)
  for the closing phase of the diphthong
• F2 falls continuously as dorso-palatal stricture
  size increases and the tongue moves back
• rise in F3 can be related to the lowering and
  backing of the tongue body causing pharyngeal
  narrowing

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• 3.3.3. Pellet position and speeds
• Fig. 6 shows the pellet position of the 4 lingual
  pellets
• T1-T4 at each of the 11 measurement points for
  female and male speakers
• transformed and normalized values are shown in
  (a)
• in (b) raw values are plotted together with
  average palate outlines and pharynx line segments
  can be seen
• arrows indicate the direction of movement over
  time
• (b) shows the mean size, shape and location of
  the male and female pellet trajectories
• in the transformed data (a), the palate has been
  flattened
• ? must be interpreted more carefully

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• Explanation of Figure 6
• both transformed and raw data bring out the
  larger male dorso-palatal strictures defined by
  T3 and T4
• laminal and apical strictures are not different
  for males and females
• transformed data encode the distance between the
  palate and the pellets
• higher location of the female trajectories shows
  the different stricture size (T3-T4)
• T-test proves that for females the palate-pellet
  distance for T3-T4 is smaller
• average lengths of the pellet trajectories during
  the vocalic stretch are shorter for females

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• posterior male lingual pellets T3-T4 travel a
  greater distance than the female pellets and they
  stay in contrast to the smaller acoustic space
  traversed by the male speakers
• these gender differences stand in contrast to
  findings in (Hashi et al. 1998) where no gender
  influence on isolated vowel tokens was found
• male dorsum travels a greater distance in a
  shorter time period (see 1.Duration) than the
  female one because the mean speed of the male
  posterior pellets (T3-T4) is higher

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• Explanation of Figure 7
• the next figure summarizes the average pellet
  speeds at each of the 11 measurement points
• for the anterior pellets T1-T2 the male and
  female speed is not significantly different over
  the whole vocalic stretch
• for T3-T4 the initial and final portions are
  similar as well
• whereas the mean speeds of T3-T4 are at the
  highest point you can see significantly higher
  male speeds
• ? compensation by both males and females is
  necessary to achieve the same targets, despite
  differences in articulatory space

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• Conclusion of Figure 7
• gender-specific stricture differences are
  restricted to posterior region of the oral cavity
  
• ? degree of male palatal doming is higher and
  creates a greater articulatory space to cross
• there are nonuniform differences in the relation
  of oral to pharyngeal cavity length and
  nonuniform differences in palate shape
• ? this has nonuniform dynamic consequences for
  tongue movement

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4. Discussion

• for the same V-V sequences male and female tongue
  movements and their acoustic and perceptual
  products are similar in shape and structure
• difference between male and female F1 increased
  acoustically with the degree of vowel openness
• male speakers had a shorter stretch duration
• ? the speed of tongue dorsum displacement was
  higher
• size of male and female articulatory spaces is
  different and stands in an inverse relationship
  to the size of their acoustic products
• for the V-V sequences male and female pellet
  tracks have a similar form and differ only in
  size and position

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• male and female speakers a operating with similar
  speeds of tongue movements
• assume that the slower (female) articulatory
  movements require more time and faster (male)
  ones less
• larger vowel space for women
• ? women speak more clearly and articulate more
  because it is the prestige form for female
• women produce longer vowels than men
• possibly speakers adopt different articulatory
  strategies to arrive at tokens of the same
  phonological categories
• ? many of the hypothetical consequences are
  speculation

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• ? no proof whether 2 speakers aim for similar
  targets when they produce tokens of the same
  phonological categories in a language
• ? no classification that tokens of the same
  phonological categories are equivalent in
  articulatory, acoustic and perceptual terms
• several experiments draw conclusions based on a
  few informants
• ? tendencies might be individual rather than
  gender based
• many reasons for difference between male and
  female speech
• ? women tend to have a greater variation in their
  speech
• ? female speech has been seen more difficult to
  analyse

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5. References

• Simpson, A. P. (2002). Gender-specific
  articulatory-acoustic relations in vowel
  sequences. Journal of Phonetics, 30(3)417-435.
• Simpson, A. P. (2001). Dynamic consequences of
  differences in male and female vocal tract
  dimensions. Journal of the Acoustical Society of
  America, 109(5)2153-2164.
• Samuelsson, Y. (2006) Gender effects on phonetic
  variation and speaking styles A literature
  study. GSLT Speech Technology Term Paper, autumn
  2006.

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• Goldstein, U. (1980) An articulatory model for
  the vocal tracts of growing children. Ph. D.
  Thesis, MA M.I.T.
• Hashi, M., Westbury, J. R. Honda, K. (1998)
  Vowel posture normalization, Journal of the
  Acoustical Society of America, 104, 24262437.
• Johnson, K., Ladefoged, P. Lindau, M. (1993)
  Individual differences in vowel production,
  Journal of the Acoustical Society of America, 94,
  701714.
• Kuehn, D. P. Moll, K. L. (1976) A
  cineradiographic study of VC and CV articulatory
  velocities, Journal of Phonetics, 4, 303320.

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• Thank you for listening!