2. The end of vowels + The beginning of fricatives November 19, 2012

3. The Road Ahead Today: finish vowels and begin fricatives… Formant plotting + vowel production exercises is due on Wednesday! This Wednesday: continue the discussion of fricatives On Friday: fricative transcription As for right now: let’s measure some formants! to prove a point: everybody’s vowel space is different.

4. Source/Filter Summary Sound sourceSound filter vocal foldsvocal tract fundamental frequencyresonant frequencies (formants) F0F1, F2, F3… harmonicsstanding waves pitch of voicevowel quality in a (wide-band) spectrogram: vertical striationshorizontal dark bands a musical analogy: stringsbody (of guitar, violin, etc.)

5. More Music With (most) musical instruments, we can only change the frequency of the sound source. Timbre is a musical term for the “quality” of a sound. I.e., its characteristic resonances. E.g., compare the same note played by a trumpet vs. a violin. In speech, you can independently change both source and filter frequencies at the same time. Like changing the size of a piano… As you press different keys on the keyboard. This makes the acoustics of speech at least twice as complex as the acoustics of music.

6. Formant-Reading Tip #1 Another distinction between source and filter characteristics is formant bandwidth. Harmonics are exact: integer multiples of source frequency Resonances are less exact: they’re centered around an optimal frequency, but other frequencies may resonate to some extent, too. Hence: formants can appear to merge in wide-band spectrograms.

7. Bandwidth

9. Merged Formants F1 F2

10. Another Problem: Dynamics “hod” F1 F2 vowel formants are typically not “steady-state” for very long F1 F2

11. Source/Filter (again) So far, we’ve considered the following source/filter configuration: source: voicing at the vocal folds filter: the resonating vocal tract Q: What would happen if we changed the source by: Opening the glottis (i.e., not voicing) And increasing airflow so that… there is some audible turbulence as the air passes through the vocal folds? A: We’d get something called whispering (technical term)

12. Whispering Example whispered“had” voiced

13. Glottal Fricatives The sound “source” of whispering is the turbulence that airflow creates as it passes through the vocal folds. “Glottal fricatives” The IPA lists two sounds as “glottal fricatives” voiceless: [h] voiced: The “filter” of both sounds is the same vocal tract shapes that we find in vowels.  In a sense, [h] is a “voiceless vowel”

14. [h] in different vowel contexts “heed”“had”

15. [h] in different vowel contexts

16. “Voiced” /h/ In English, /h/ often surfaces as breathy voiced when it appears between two vowels. “ahead” “head”

17. Turbulence Acoustics The “source” of fricative sounds is aerodynamic turbulence aperiodic random Aperiodic sounds are noisy Their pressure values vary randomly over time waveform snippet of aperiodic “white noise”:

18. White Noise Spectrum Recall: white light is what you get when you combine all visible frequencies of the electromagnetic spectrum White noise is so called because it has an unlimited range of frequency components

19. White Noise Spectrogram

20. Fricative Filtering The sound source of fricatives resembles white noise. …but this aperiodic noise may be filtered by the vocal tract in the same way that voiced vowels are. Ex: [h] tends to take on the spectral characteristics of its surrounding vowels  [h] just replaces the voicing source with an aperiodic sound source. = coarticulation

21. Fricative Place of Articulation A fricative’s place of articulation is where, in the vocal tract, its turbulence noise is made. Fricatives may be produced at essentially any place of articulation. At different places of articulation, fricatives will have: Different filters based on the area and shape of the vocal tract in front of the obstruction of the airflow Different sound sources based on the flow of air through the obstruction

23. Glottals, Epiglottals, and Pharyngeals Glottal fricatives: [h] Epiglottal fricatives: Pharyngeal fricatives: Note: try not to confuse the symbols for the: voiced epiglottal fricative voiceless epiglottal stop And also not the symbols for the: voiced pharyngeal fricative glottal stop

24. Agul Glottals, epiglottals and pharyngeals contrast in the Caucasian language Agul.

25. Uvular Fricatives

26. Uvular Fricative Symbols Peter says: Uvular fricatives contrast with pharyngeals and glottals in one dialect of Hebrew.

28. Palatals and Velars

29. Palatal and Velar Symbols <-- Peter says Possible confusion #1: voiceless palatal fricative[ç] voiceless palatal stop[c] Possible confusion #2: voiced palatal fricative voiced palatal stop Possible confusion #3:

30. Greek

31. Coronal Fricatives Peter says: The coronal fricative landscape is very complex. Next time we’ll look in detail at how coronal fricatives are produced in: English Chinese Polish

32. Toda Toda is spoken in southern India.

33. Toda Mid-Sagittal Diagrams

34. Bilabial Fricatives Bilabial fricatives exist allophonically in some languages (e.g., Spanish) They were not recognized as a potentially contrastive sound until relatively recently (‘70s or ‘80s) it was discovered that they contrasted with labio- dental fricatives in Ewe, a language spoken in Ghana.

35. Ewe