Understanding Fricatives and Turbulence Sources in Articulation

1. Fricatives, part II November 21, 2012

2. Announcements • For Friday: spectrogram matching exercise! • Fricatives and possibly glides, too. • Final exam has been (re-)scheduled: • Tuesday, December 18th, 9:00-11:00 • Science B 146

3. 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 flow of air through the obstruction

4. Turbulence Sources • For fricatives, turbulence is generated by forcing a stream of air at high velocity through either a narrow channel in the vocal tract or against an obstacle in the vocal tract. • Channel turbulence • produced when airflow escapes from a narrow channel and hits inert outside air • Obstacle turbulence • produced when airflow hits an obstacle in its path

5. Obstacles, Channels, Walls • General rule of thumb: obstacle turbulence is much noisier than channel turbulence • [f] vs. • Also: obstacle turbulence is louder, the more perpendicular the obstacle is to the airflow • [s] vs. [x] • [x] is a “wall fricative” • Rule of thumb: voiced fricatives are hard to make. • In fact, fricatives are kind of hard to make in general.

6. Fricatives = difficult • Fricatives require great articulatory precision. • it’s necessary to create a narrow channel through which air can flow. • (and hold it) • ballistic vs. controlled articulations • Some data for [s]: (Subtelny et al., 1972) • alveolar constriction  1 mm • incisor constriction  2-3 mm • Larger constriction sizes result in -like sounds • Also: voiced fricatives are even more difficult • Why?

7. Some Typology • Languages with the following number of fricatives • From the UPSID database (total of 316 languages) • Voiceless Voiced Voiced/Voiceless • [s] 266 [z] 96 0.36 • 146 51 0.34 • [f] 135 [v] 67 0.50 • [x] 75 40 0.53 • 29 13 0.45 • 21 32 1.52 • 18 21 1.16

8. Some Typology • Languages with the following number of fricatives • From the UPSID database (total of 316 languages) • Voiceless Voiced Voiced/Voiceless • 21 32 1.52 • 18 21 1.16 • 17 3 0.17 • [ç] 16 7 0.43 • 13 9 0.69

9. Aerodynamics • Note: voiced fricatives have two sound sources. • one at the glottis • one at the fricative constriction • In voicing, air rushes through the glottis in short, regular bursts • Glottis is closed part of the time •  Difficult to maintain a steady stream of flowing air at the fricative constriction. •  Frication (second source) can be lost

10. vs. [s] [z]

11. Some More Typology # of Fricatives # of languages % of total 0 21 6.6% 1 37 11.7% 2 62 19.6% 3 47 14.8% 4 37 11.7% 5 26 8.2% 6 28 8.8% 7 19 6.0% 8 20 6.3% > 8 22 6.4%

12. Fricative Fun Facts • Of the 21 languages without any fricatives, 15 are Australian languages • Hawaiian is another example • Australian languages also tend to lack affricates • But remember: many Australian languages have five or more place contrasts for stops. • Kabardian has the most fricatives: 22 • Kabardian also has 2 (count ‘em) vowels • Languages with one fricative: [s] • Languages with two fricatives: [s], or [s], [f] • Languages with three fricatives: [s], , [f]

13. Sibilants • [s] and are known as sibilant fricatives • Sibilants have more acoustic energy at higher frequencies than other fricatives • Two reasons why: • they are obstacle fricatives • = the back of the upper teeth •  louder than other fricatives • small, short resonating filter • = between constriction and the lips •  higher frequencies resonate

14. [s] vs. [f] “sigh” “fie” • Note: acoustic energy for [f] is weaker, and spread more evenly across all frequencies

15. vs. “shy” “thigh”

16. vs. [s] “sigh” “shy”

17. Acoustic Enhancement • Note: is post-alveolar and [s] is alveolar •  more space in vocal tract in front of • including a “sub-lingual cavity” • This “filter” of resonates at lower frequencies • In English, this acoustic distinction is enhanced through lip rounding for • this extends the vocal tract • further lowers the resonant frequencies of

18. The Sub-lingual Cavity • Let’s check the videotape...

19. Behind the Constriction [s] • Let’s check the ultrasound…

20. Other Examples • Susie and David say “speech”: • Also: Where the shtreets have no name • Or: Tina Fey • Note: there are no word-initial /sr/ sequences in English. • “shriek” *“sreek”

21. Polish • Note: lip-rounding can be used to enhance other fricative contrasts • In Polish, it enhances the contrast between (post-)alveolar and dental fricatives • the (post-)alveolars have the rounding

22. Polish, continued • Polish also has what are known as alveolo-palatal fricatives. • = constriction in the post-alveolar region • + raised tongue in the palatal region (behind the fricative)

23. Polish Sibilants

24. vs.

25. Palatography [kasa]

26. Palatography

27. Polish Clusters • Just for kicks...

28. Four Fricatives