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Basic Spectrogram & Clinical Application: Consonants.

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Presentation on theme: "Basic Spectrogram & Clinical Application: Consonants."— Presentation transcript:

1 Basic Spectrogram & Clinical Application: Consonants

2 Sonarants Consonant that manipulates vocal tract resonance Characteristics –F2 & F3 formant changes –Transitions Include: –Nasals /m/, /n/ & /  / –Liquids /r/, /l/ –Glides /w/, /j/

3 Sonorants Production involves a greater constriction when compared to vowels and a quicker more extreme movement of the vocal tract compared to diphthongs Movements and formant transitions slower than all other consonants

4 Nasals Low frequency energy (near Fundamental Frequency)- Nasal Murmer Place of nasal articulation is defined by the 2nd formant transition & place of antiresonances

5 Spectrogram: Nasals Nasal Murmur mnaa

6 Glides Semivowels /j, w/ Gradual transitions that appear on the spectrogram as a slowly changing formant pattern –Formant transitions: Duration= ms

7 Spectrogram: Glides

8 Liquids Liquids /l, r/ Formant pattern steady state and transition is the primary acoustic cue –Prolongation effects /l/ steady state formants –F1= 360 Hz –F2= 1300 Hz –F3= 2700 Hz /r/ steady state formants –Same F1 & F2 as /l/ but much lower F3

9 Spectrogram: Liquids r l

10 Stops –Acoustic Cues: Silent or low energy interval, burst, transition Silent interval = oral constriction (I.e. closure of lips for /b/); also termed a stop gap –Voiced stops can be seen on the voice bar as noise energy Burst = Articulatory constriction is released; energy released looks like noise on the spectogram Transition= formant transition into following vowel

11 Stops Bilabial Stops (/p/, /b/): –F1 starts at zero & rises to F1 of next vowel –F2 starts at 800 Hz & rises to F2 of following vowel –F3 increases for following vowel Alveolar Stops (/t/, /d/): –F1 same as for bilabial stops –F2 starts at 1800 Hz & rises to F2 of following vowel Velar Stops (/k/, /g/): –F1 same as for bilabials –F2 has 2 starting points 1300 & 2300 Hz

12 Spectrogram with Transitions: /d a d/

13 Voiceless Stop Consonants

14 Stops Characteristics: –Voice onset time (VOT)= time between stop release (burst) and the onset of glottal pulsing Voiced= shorter VOT Longer VOT in cleft palate, dysarthric speakers and phonological disorders

15 Fricatives Spectrum of noise is the acoustic cue & formant transition Specific location of turbulence –Labiodental /f,v/ Low energy, flat diffuse spectra (front cavity is short with little filtering effect on noise energy) –Linguadental /  ð/ Low energy, flat and diffuse spectra (front cavity gives little shaping to spectrum) –Lingu-alveolar /s, z/ High energy noise spectra, energy lying in high frequencies (above 4 kHz) (front cavity longer contributing to distinctive spectral shaping) –Linguapalatal / sh, zh/ Intense noise spectra, energy lying in mid to high frequencies (above 2kHz) (front cavity significant resonance effect)

16 Spectrum: Changing Pattern of Fricative Noise

17 Fricatives: Spectrum Higher energy spectraLow to mid energy spectra

18 Affricates Affricate consonants have a stop gap (silence, low energy interval) followed by intense frication –Stop gap= articulatory closure –Frication= noise after closure is released

19 Spectrogram: /judge/

20 Laboratory Part I: SONORANTS: –Nasal Consonants Make a wide-band spectrogram of: “mow”, “no” –Draw a vertical line where consonant ends and vowel begins –Locate nasal murmer, 1st & 2nd formants, antiresonances –What spectral differences do you see? –Locate the 2nd formant transitions on both. What are the differences? “Some”, “Sun” –Label the same as the first spectrogram Contrast both spectrograms

21 Laboratory Part II: Approximants –Glides & Liquids Wide band spectrogram of “a ray”, “a lay”, “a way”, “a yea” Label each phone on the spectrogram Compare /r/ & /l/ Determine the relative frequency of F1, F2 & F3 Determine whether there is acoustic energy present at higher frequencies is low or high What acoustic characteristics are different between consonants?

22 Laboratory Part III: Silibants –Fricatives Say “sigh” and “shy” at a moderate rate Obtain a wide-band spectrogram (at least 8 kHz) Locate & label each phone What are the spectral characteristics that distinguish it from vowels and other consonants?

23 Laboratory Part II: Nonsilibnts –Obtain a wide-band spectrogram of “high”, “fie” and “thigh” Label each phone What spectral features distinguish phones? How do they differ from silibants? –Obtain a wide-band spectrogram of “ether” and “either” –Label


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