Basic Spectrogram

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Basic Spectrogram Clinical ApplicationLab 9
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Spectrographic Features of Vowels

• 1st formant carries much information about
  manner of articulation
• Vowel, consonant
• Vowels, dipthongs semivowels- spectral energy
  is clustered in formants
• 1st 3 or 4 being important for ecognition
• Vowel sounds appear on spectrograms as bands of
  energy that run horizontally

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Spectrographic Features of Vowels

• All English vowels can be recognized on the basis
  of the fist 2 formants (F1 F2)
• Thus each vowel can be represented as the
  relative position of the fist two formants
• F1 Variation in TONGUE HEIGHT
• F2 Variation in TONGUE ADVANCEMENT (front -back)

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Two Formant Spectrograms Front, Back Central
Vowels
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Phonetic Quality of Vowels

• Front Vowels
• Larger separation between F1 F2
• Small F2 F3 separation
• Frequency of F1 Tongue height
• Back Vowels
• Small separation between F1 F2
• Large separation between F2 F3
• Central vowels
• Formant frequencies are evenly spaced
• Moderate jaw opening causes mid-range F1

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F1/F2 Plots of Vowels (Vowel Quadrangle)
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Vowel Spectrograms (Wide Band)
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Laboratory Vowel Formants

• Frequency values of vowel formants depend on the
  length and shape of the vocal tract
• Vocal tract length configuration
• Accuracy of production

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Laboratory

• Part I Measuring formant frequencies
• Wide band spectrogram of She saw ten tops
• Identify the 4 vowels formant bands
• Why do formant bands change across the syllable
• Measure F1 and F2 for each vowel
• Half of formants thickness
• Measure at stable portion of vowel and midpoint
• Norms compared to measured values
• Measure F1 F2 of the vowels and draw in on
  example

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Laboratory

• Part II Graphic analysis of formants
• Use spectrograms of vowels provided
• Adult male
• Adult female
• Child
• Measure F1 F2 of each vowel
• Make a spectrogram of all the vowels

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Laboratory

• Part II Continued
• Graph 1- plot the formant frequencies of the
• Female in RED
• Male in BLUE
• Child in GREEN
• Explain the relationship between what you just
  plotted and a standard vowel quad
• Connect all the /i/ and /æ/ points from each
  speaker
• Plot F1 F2 for the articulatory disordered
  patient