Ultrasound-based tongue root
imaging and measurement
James M Scobbie
QMU
With thanks to collaborators
Jane Stuart-Smith, Marianne Pouplier, Alan
Wrench,
Eleanor Lawson, Olga Gordeeva
• Pros and cons of Ultrasound Tongue Imaging
• EPG/UTI experiment on English /l/
– Alveolar contact or vocalisation
– Light and dark allophones of /l/
• The ECB08 UTI corpus
– Scottish derhoticisation and articulation of /r/
– Vowel system
– A handful of /l/ again…
• Demo of AAA software
Introduction
2
• From qualitative “transcription” to quantitative
laboratory-based studies with stabilisation
UTI
3
• Pro
– Tongue root to blade in one image
– Instant, real-time, easy, safe, cheap
– Qualitative and quantitative analysis
– Can be combined with other techniques
• Con
– Image quality is variable
– Hardly any constriction or info on passive articulator
– Frame rate of video output is only ~30Hz (~33ms)
– Synchronisation with acoustics is problematic
– Quantitative analysis is time-consuming and as yet
poorly developed… what to measure?
Pros and cons of UTI
4
Future: corrected high speed data
5
• /l/ is lighter in onset, darker in coda
• Many accents have “vocalisation” in coda
• EPG + UTI study of 10 speakers
– UTI image quality uniformly awful 
– EPG results very interesting 
– Context was /i/+/l/ (+ {/b/, /h/, /l/}) +/i/
• Pee leewards, peel beavers, peel heaps of, etc.
• EPG results
– Reduction or loss of alveolar contact in codas
– Reduced palatal contact (compared to /i/) due to /l/
English /l/
6
• Alveolar contact in orange, palatal in green
• S2 typical in losing palatal contact in onset
(can we pee
leeward
in a gentle
breeze)
Example onset
7
• No alveolar contact,
more palatal contact
(can we peel
BBC advertising
from the shop window)
Example coda_b retraction
8
•
•
•
•
E + S1: light onset and dark coda in palatality
Scots S2,3,4 show darker (less [i]-like) onset
Question 1: what about intergestural timing?
Question 2: what about the pharyngeal aspect
of darkness rather than loss of palatality?
Onset
ambi
Coda_b
100%
60%
40%
40%
20%
0%
0%
E2
E3
Speaker
E4
E5
gem
Coda_h
60%
20%
E1
Onset
ambi
Coda_b
80%
Contact i-Zone
Contact i-Zone
80%
100%
gem
Coda_h
S1
S2
S3
S4
Speaker
EPG results: loss of palatal contact
9
• Relatively simultaneous alveolar contact and
loss of palatality in onset
• Alveolar contact is delayed in coda (or missing)
and loss of palatality occurs earlier
120
100
80
Lag (ms)
60
40
S
E
20
0
-20
onset
gem
ambi
coda_h
coda_b
-40
-60
context
EPG results: timing
10
Coda = vocalised and darker
11
• Measurement of Tongue root retraction in [i]
and in [l] for a single sample speaker S2
– Coping with terrible quality UTI
• Find frames of maximum advancement and
maximum retraction of root just above hyoid
shadow)
– Typical problems in measuring images
UTI: Scottish pharyngealisation?
12
• Poor image quality
• Time and location of root: top of hyoid shadow
Example onset
13
• This is only a bit better than guessing, but
impression is of slight pharyngealisation
Example onset
14
• Tongue root retracts earlier in coda_b (p<0.01)
– Max advancement appears to be near end of [i] vowel in
onset condition and mid-way through [i] in coda_b condition
– Max retraction apparently at end of [l] in onset condition
and towards the end of [b] in coda_b condition
• [i] is less advanced in coda_b than onset (p<0.005)
– There is a n.s. trend for greater pharyngealisation in coda [l]
retraction distance
200
5
150
4.5
mm
ms
retraction duration
100
4
50
3.5
0
3
onset
coda_b
Results (S2, n = 18)
onset
coda_b
i
l
15
• Darkness as measured by decrease in
palatality in /i/ context shows onset/coda
differences for only some speakers
– Probably dialectal: Scots /l/ is less [i]-like in onset
• “All” speakers show a strong timing difference
– Front and back gestures dissociate in coda so that
posterior gesture is earlier and alveolar (if present
at all in coda) is later (“gestural dissociation”)
• Qualitative (and quantitative) analysis of UTI
data probably shows greater pharyngealisation
for all speakers’ coda than onset.
Conclusions
16
• Ultrasound/acoustic corpus
– 15 teenagers (12-14) in friendship pairs (+4 11yrs)
– Wordlist and some spontaneous discourse
– Half from a WC and half from a MC school
– Main purpose to test effect of use of UTI on
vernacular speech variables
• Secondary purpose
– Derhoticisation of coda /r/ - pharyngealisation?
– Vowel space
• But sadly not much room for
– Vocalisation of coda /l/ - pharyngealisation?
ECB08
17
Hiya my name's Kaj McInally
My company's FinesseDecor (Scotland) Ltd
I'm not a manager. I'm a painter and decorator
to trade, first and foremost
who just so happened to start work for myself, and
then
we’ve been that... kinda... successful that we've had
to take on people
Derhoticised coda /r/
18
• Since the 1970s coda /r/-“loss” has been reported in
working class speech
– Not the RP-like middle-class non-rhoticity
• Stuart-Smith (2003) in a Glasgow corpus including 1415 year old children showed that WC girls have no
overtly rhotic consonant for coda /r/ in approximately
90% of cases, boys in about 80%
– Middle class children and older adults are rhotic, so the
stratified derhoticisation is indicative of change in progress.
– /r/ seems to be turning into a vowel right now
– Strong impression of pharyngealisation offglide on vowels
with monophthongal pharyngealisation on low back ones
Losing /r/ in Scotland
19
F3
F2
rain, with an anterior
approximant, usually
described as being
“retroflex” (note low F3)
ferry, with a tap (an
approximant is more
common)
Typically rhotic tokens of Scottish /r/
20
F3
F2
F3
F2
Derhoticised ear (above)
car (below)
Rhotic ear (above)
car (below)
F3
F2
Word-final derhoticisation in ECB08
F3
F2
21
• Lexical sets BIRD WORD HERD merged (8/11)
– Earth, verb, berth, (err) = third, word, surf, birth, fur
– Could be a rhotic vowel /ɚ/
• No /a/ split (Pam/palm are homophones)
• /ʉ/ is central and not very high
i ʉ
o
iɹ ʉɹ oɹ
e ı
ɔ
eɹ ɚ
ɛ a
ʌ
ɑɹ
Rhotic (MC) speakers
ɔɹ
22
300
o
i
e
u
F1 (Hz)
Dimension 1
ɪ
ɔ
ɛ
ʌ
a
1300
3300
MC Edinburgh
F2 (Hz)
Dimension 2
800
23
300
o
i
ɪ
F1 (Hz)
ɛ
Dimension 1
ɔ
u
e
ʌ
a
1300
3300
F2 (Hz)
Dimension 2
WC West Lothian
800
24
• Phonologically, only /ɛ I / are “lax”
Articulation of vowels (EF4)
25
• Tipup (LM17 onset) or tipdown (LM15 onset)
Sample ultrasound images of /r/
26
Tongue blade
raising
[he]
[ɹ]
Tongue root
retraction
[ɹ]
[he]
[ə]
Waterfall time sequence: hair
27
• More vowels (and environments) with weak /r/
– No merger of /ɛr/ and /ʌr/ (8/8)
– /a/ split (hat/heart) [a] vs. [ɑ] for the most derhotic
– /ʌr/ is short without compensatory lengthening
– High vowels create diphthongs
– Pre-pausal /r/ tends to devoice
• Potential /ʌ/ merger (hut/hurt, bud/bird)
i ʉ
o
iə ʉə oʌ
e ı
ɔ
eə
ʌ
ɛˤ ɑː 
ɛ a
ɔˤ
(ʕ)
Derhoticising (WC) speakers
28
Pre-pausal /r/ may have late (covert?) tip
•
Low vowels sound derhoticised, acoustically
lack F2/F3 approximation, and are near-monophthongs.
•
Articulatorily a clear rhotic gesture was retained
car
29
Covert rhoticity occurs even in weak
syllables and in spontaneous speech
30
• What about /l/?
– If dark, is it pharyngealised?
– If vocalised, is it a pharyngeal?
– How are derhoticised /r/ & vocalised /l/ kept apart?
– Hip
hum
hut
– Fur/fir
hurt
– Pill
film
– Mull bulb
cult
• Clear difference between /r/ and /l/ in open and
closed syllables
/l/ in a derhoticising (WC) speaker
31
– Red = // mull (cons) & bulb (vocalised)
– Blue = /ı/ film (cons) & pill (vocalised)
• Pharyngealisation vs. velarisation?
UTI of laterals
32
– Red = cult (cons /lt/)
– Green = hurt (cons /t/)
• /l/ pharyngealised + velarised?
• Pharyngealised postalveolar /r/ with saddle
UTI of laterals
33
• Pharyngealisation and velarisation more
extreme than in vowels
/l/ compared to /o/ and /ɔ/
34
• Onset/coda differences in /l/ in a high vowel
context are well-known to involve loss of
palatality and a greater pharyngeal constriction
(Sproat and Fujimura 1993), plus subtle loss of
alveolar contact (eg Giles & Moll)
• Scottish speakers who have no onset/coda
difference in palatality do show increased
pharyngealisation in coda (and may show very
strong vocalisation, not gestural undershoot)
• Vocalised /l/ may be velarised while
pharyngealisation occurs for consonantal /l/
Conclusions
35
• Derhoticisation often sounds like
pharyngealisation
• But in prepausal and other masking contexts
there can be delayed covert post-alveolar
constriction, due to “gestural dissociation”
• WC /r/ seems to be changing from consonant
into vowel, with some increase in vowel space
• Meanwhile, MC rhotic speakers merge vowels
• WC /l/ and /r/ seem to be keeping distinct
– Is the pharyngealised /l/ also velarised?
– Is the difference purely anterior?
Conclusions
36
• Let’s look at pharyngealisation in a derhoticising
speaker
– Hut vs. hurt
– Bud vs. bird
– Far vs. fir
AAA demo
37
Who says you need ultrasound?
38