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Sounds that “move”. Diphthongs, glides and liquids. The important role of movement. Articulatory movement = spectral change Spectral change occurs as speakers transition within and between sound sequences Spectral change plays a significant role in Perception of certain speech sounds
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Sounds that “move” Diphthongs, glides and liquids
The important role of movement • Articulatory movement = spectral change • Spectral change occurs as speakers transition within and between sound sequences • Spectral change plays a significant role in • Perception of certain speech sounds • Overall speech intelligibility
Diphthongs • Slow gliding (~ 350 msec) between two vowel qualities Components • Onglide- starting point of articulation • Offglide-end point of articulation • Articulatory Transition = formant transition • Diphthongization: articulatory movement within the vowel • Varies by geographic region
American English Diphthongs • // - “bye” • // - “bough” • // - “boy” • // - “bay” • // - “bow”
What cues listeners? (Nábĕlek et al., 1993) Question: • What spectral temporal variables contribute to distinction of // vs. //? • Does the quality of listening environment or hearing ability of the listener influence those factors? Control variables • Rate (Hz/msec) and Duration (msec) of formant transition Results • // is perceived for • ↓ transition rates of ↑ duration • ↑ transition rate of ↓ duration
What cues listeners? (Nábĕlek et al., 1993) Results continued, • Ambient noise had a larger effect on • ↑ transition rate, ↓ duration condition • Hearing Impairment differentially affected • ↑ transition rate, ↓ duration condition Conclusion • Fast, short transitions and slow long transitions can both serve to cue listeners to diphthongs • Slow, long transitions are more resistant to • Poor listening environments • HI listeners
diphthong duration vs.speech clarity rating From Tasko & Greilick (2010)
Degree of Constriction Greater than vowels Poral slightly greater than Patmos Less than fricatives Poral for glides/liquids < Poral for fricatives Constriction lasts ~ 100 msec Constriction results in a loss in energy weaker formants Transition rate faster than the diphthongs slower than the stops lasts ~ 75-250 msec Glides (/w/, /j/) & Liquids (/l/, /r/) Associated with 1. high degree of vocal tract constriction 2. articulatory transition
Place: labial Acoustics /u/-like formant frequencies Constriction formant values F1 ~ 330 Hz F2 ~ 730 Hz weak F3 (~ 2300 Hz) /w/ Freq (Hz) 3000 F3 2000 F2 1000 F1 V V w
Place: palatal Acoustics /i/-like formant frequencies F1 ~ 300 Hz F2 ~ 2200 Hz F3 ~ 3000 Hz 3000 F3 2000 F2 1000 F1 V j V /j/ Freq (Hz)
/j/ V j V
Liquids (/l/, /r/) • lateral /l/ • Rhotic /r/ • Pickett (1999) considers these consonants glides as well
Place: palatal Articulatory phonetics Variable tongue positions “bunched” “retroflexed” Allophonic Variations Some suggest “dark” (CV) –very low F3 “light” (VC) –F3 not as low Acoustics Hallmark of /r/ is a low F3 F1 ~ 350 Hz F2 ~ 1050 Hz F3 ~ 1550 Hz Vowels have F3 above 2200 Hz Vowels around /r/ are colored or F3 values lower than usual /r/
/r/ Freq (Hz) 3000 F3 2000 F2 1000 F1 V r V
/r/ “coloring” of vowels // //
Point parameterized representation Retroflexed
Between-speaker variation “row” “row” JW39 tp004 JW45 tp004 Very common
Within-speaker variation: different context “row” “dorm” JW37 tp009 JW37 tp099 Common
Within-speaker variation: same context “right” “right” JW37 tp009 JW37 tp099 Not common, but possible!
N=53 normal speakers Not just two different configurations, but a whole family of possible configuration From Westbury et al. (1998)
How can these vastly different tongue configurations lead to similar acoustic/perceptual consequences?
Summary • There is a wide distribution of articulatory configurations for /r/ • Different articulatory configurations of /r/ are indistinguishable acoustically and perceptually • Different tongue configurations can produce equivalent area functions • Some parts of the area function are more critical than others for determining key acoustic/perceptual effects
Clinical Digression • Clinically, /r/ is a difficult sound for children to learn. • Is there anything from our discussion that might suggest why this might be the case?
Place: alveolar Articulatory phonetics: tongue tip contacts alveolar ridge, splitting the vocal tract Introduces antiformants Acoustics F1 ~ 360 Hz F2 ~ 1300 Hz F3 ~ 2700 Hz F2 is variable and affected by vowel environment Transition often looks more abrupt than other sounds discussed Allophonic variations Light /l/: CV environment Dark /l/: VC environment /l/
/l/ Freq (Hz) 3000 F3 2000 F2 1000 F1 V l V
/l/ V l V