Fricatives + Voice Onset Time March 31, 2014

In the Year 2000 Today: we’ll wrap up fricatives… and then move on to stops. This Friday, there will be one final transcription exercise. On Bengali, Quebecois French, and Arabic. I just posted it right before class.

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”

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

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)

Polish Sibilants

vs.

Palatography [kasa]

Palatography

Polish Clusters Just for kicks...

Four Fricatives

Mandarin Sibilants Mandarin Chinese also has dental, post-alveolar and alveolo-palatal sibilant fricatives. The post-alveolars are sometimes retroflex

Mandarin

Before I forget… There are two remaining fricative symbols in the IPA that we have yet to learn. 2.In Swedish, there is a fricative which combines the articulations of post-alveolar and velar [x]: 1.Some dialects of English still have a voiceless labio-velar fricative (a voiceless /w/):

Affricates Affricates are transcribed as stop-fricative sequences Acoustically, amplitude rises faster in affricates than in plain fricatives “rise time” Phonologically, affricates are [-continuant]

Affricate Typology More numbers from the UPSID database: 522 affricates in 316 languages 141 [ts]95 80 [dz] affricates have sibilant fricatives Other affricate types are rarer: [pf] (German)[tx] (Navajo)

Fricative vs. Affricate “shy” “chime”

Polish, Again Polish contrasts affricates with stop + fricative sequences

Stop + Fricative vs. Affricate

Fricative Acoustics Summary Turbulence provides the source of fricative noise Voiced fricatives also have a sound source at the glottis Obstacle turbulence tends to be louder than channel turbulence Sibilants are particulary high in intensity The filter of fricative turbulence noise changes depending on the place of articulation sibilants: very short filter, emphasizing high frequencies labials: essentially no filter (flat spectrum) back fricatives: longer, more vowel-like filter Affricates: stop-fricative sequences with shorter rise time

Review: Stops and Voicing Stops Three stages: close, maintain, release Pressure build-up behind closure “Release Burst” Voicing Vocal folds are lightly brought together (adducted) Sub-glottal pressure higher than supra-glottal pressure Airflow through glottis causes cycle of vocal fold opening and closing Voiceless: k > t > pVoiced: b > d > g

It’s not that simple The voicing of stops is difficult, so the contrast between voiced and voiceless stops often takes a different form Making use of a different property: aspiration An aspirated stop has the following timing: 1.Stop closure is made 2.Airflow builds up pressure behind closure 3.Closure is released (with a “burst”) 4.Air flows unimpeded through glottis (“aspiration”) 5.Vocal folds close; voicing begins

An Aspirated Stop: [p h œt] release burst aspiration voicing (vowel)[t] closure [t] release burst

An Unaspirated Stop: [pœt] release burst voicing (vowel)

A Voiced Stop: [byt] release burst voicing (vowel) voicing (closure)

Voice Onset Time Voice Onset Time (VOT) is defined as the length of time between the release of a stop closure and the onset of voicing. For aspirated stops--voicing begins after the release, so: VOT  milliseconds For unaspirated stops--voicing begins at the release, so: VOT  milliseconds For voiced stops--voicing begins before the release, so: VOT < 0 milliseconds (VOT can be negative)

Thai Stops In stressed onset position, English distinguishes between: unaspirated and aspirated stops. Languages like French, Dutch and Spanish distinguish between: voiced and voiceless unaspirated stops. Thai splits up the VOT continuum into three parts: voiced, voiceless unaspirated, voiceless aspirated

Thai Stops

[ba] [pa]

English Stop Contrasts 1.In onset position: /p/ is voiceless aspirated /b/ is voiceless unaspirated 2.In medial position (between voiced segments): /p/ is voiceless unaspirated /b/ is voiced 3.After /s/, in the same syllable: only voiceless unaspirated stops (no contrast)

Beak, Peak, Speak

Rabid vs. Rapid

English Stop Contrasts 4. In syllable-final position: vowels preceding /p/ are short vowels preceding /b/ are longer /p/ closure tends to be longer than /b/ closure Moral of the story: Phonological voiced vs. voiceless contrast in English is abstract It may exhibit different phonetic manifestations Phonemes vs. Allophones