Presentation on theme: "Fricatives, part II March 26, 2014 Don’t Forget! Formant plotting + vowel production exercises is due at 5 pm today! On Friday: fricative spectrograms!"— Presentation transcript:
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.
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
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.
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?
Some Typology Languages with the following number of fricatives From the UPSID database (total of 316 languages) VoicelessVoicedVoiced/Voiceless [s]266[z]960.36 146510.34 [f]135[v]670.50 [x]75400.53 29130.45 21321.52 18211.16
Some Typology Languages with the following number of fricatives From the UPSID database (total of 316 languages) VoicelessVoicedVoiced/Voiceless 21321.52 18211.16 1730.17 [ç]1670.43 1390.69
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
Some More Typology # of Fricatives# of languages% of total 0216.6% 13711.7% 26219.6% 34714.8% 43711.7% 5268.2% 6288.8% 7196.0% 8206.3% > 8226.4%
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]
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
[s] vs. [f] “sigh”“fie” Note: acoustic energy for [f] is weaker, and spread more evenly across all frequencies
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
The Sub-lingual Cavity Let’s check the videotape...
Behind the Constriction [s] Let’s check the ultrasound…
Other Examples Susie and David say “speech”: Also: Where the shtreets have no name And: Tina Fey Note: there are no word-initial /sr/ sequences in English. “shriek”*“sreek”