FORMANT FREQUENCY DISTRIBUTIONS FOR VOWELS

• Recall the Peterson-Barney vowel data:
  
  

  Mean formant values of 33 male speakers for ten American English vowels. (Data from: G. Peterson and H.L.Barney, "Control Methods Used In A Study Of The Vowels," Journal of the Acoustical Society of America, vol. 24, pp. 175-184, 1952. Figure from: Projektit: Vowel Charts.)

  
  
• What causes this natural variation?
  
  
• Is this type of variation desirable?
  
  
• How can we offset this variation?