Basic Spectrogram & Clinical Application Lab 9

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

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

Two Formant Spectrograms: Front, Back & Central Vowels

Phonetic Quality of Vowels n Front Vowels: –Larger separation between F1 & F2 –Small F2 & F3 separation –Frequency of F1= Tongue height n Back Vowels: –Small separation between F1 & F2 –Large separation between F2 & F3 n Central vowels: –Formant frequencies are evenly spaced –Moderate jaw opening causes mid-range F1

F1/F2 Plots of Vowels (Vowel Quadrangle)

Vowel Spectrograms (Wide Band)

Laboratory: Vowel Formants n Frequency values of vowel formants depend on the length and shape of the vocal tract –Vocal tract length & configuration –Accuracy of production

Laboratory n 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

Laboratory n 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

Laboratory n 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