Getting at variation with ultrasound:

Scottish and Dutch /r/

Ultrafest 3University of Arizona at Tucson

14-16 April 2005

James M Scobbie (QMUC)Koen Sebregts (Utrecht)

and thanks also esp. to Alan Wrench and Yolanda Vasquez Alvarez

Why /r/? Why ultrasound?

• Previous articulatory studies of /r/– There is a lot of variation

• Variation, change, acquisition, phonetics– “labiodentalisation” of /r/ in Anglo English– “vocalisation” of final /r/ in Scottish English– “retroflexion” of final /r/ in Dutch

• Phonology – what *is* an /r/ anyway?• Ultrasound

– Relatively informal– Can provide dynamic images

Can we add to MRI?

• Tiede’s beautiful images (from ICPhS 03)

Can we add to MRI?

• And perhaps what we can expect…

Can we add to MRI?

• And perhaps what we can expect…

Can we add to MRI?

• Tiede’s beautiful images (from ICPhS 03)

Problems with ultrasound

• The usual – Incomplete images, no passive articulator– Head-probe correction or control– Synchronisation and low frame rate– Splines and edges– Stats

• plus… – European video output (PAL) is at 25Hz

(albeit with more pixels, esp in raw AVI) – Fieldwork taped data is slower to prepare

Data collection – the laboratory

• Good – Helmet (or other head games)– Less environmental noise– The experimenter is in control– Choice of equipment and software - demo

• but… – Willing and normal subjects have to be found– Experiment costs – Intimidation of subjects

Data collection – the “field”

• In this case – Glasgow Science Centre• Good

– Lots of varied and willing subjects– Outreach… and publicity (!)– Vernacular speech more elicitable– Qualitative articulatory transcription - demo

• but… – Things are a little out of control (cf feedback)– Small amount of time for each subject – Non-ideal equipment and methodology

What do we want for /r/?

• Varied vowel environments• Varied word and syllabic positions• Acoustic analysis (and other channels?)• Info on multiple articulators • Stratified pool of subjects• Normal vernacular speech• Dynamics• Synchronised data

Backstep: methodological issues

• Smearing of raw data due to scan rate • Creating of video output - downsampling

and synchronisation problems

Ultrasound e lem ent echo response buffe rs(one pe r e lem ent) f illed cyc lic ly f rom le f t to right

Matrix of raw data

generated at the scan rate of the ultrasound machine e.g 72 complete scans per

second

Matrix of raw dataImage processing

Buffer of image data

Video scanningBuffer of image data

Smooth greyscale image buffer i.e. video

output

What’s the delay?

Methodological issues

• There is always a delay– Our range was 20ms to 100ms (mean 40ms)– Does our 25Hz rate make it clearer or worse?

• Practicalities– Multichannel synchonisation, even video,

even acoustics, is based on unpredicatable delay whether via camcorder or direct

– Individual video frames can be arbitrarily split in addition to overlay and interlacing

– High ultrasound sample rate alone is not enough

Scottish background

• Field work in Glasgow Science Centre• Stuart-Smith et al discover heavily

retracted coda /r/ in young (teenage) vernacular Scots– Not “vocalisation” like middle class

Anglification– Strong breaking (transitioning) with limited

time at target?– Different target?– Limited evidence of mergers (yet)

Scottish pilot

• Methodological– Probability of numerous subjects (hundreds)– All age groups, wide spectrum of social mix– Handheld probe plus mike mix to tape – Eyeball qualitative analysis is highly feasible– Need lab-based follow-up for quantitative

research

• Descriptive so far (very sketchy!)– Clear and obvious cases of pharyngeal /r/– No meta-linguistic awareness of change

Scottish hypotheses & implications

• Strong breaking in coda is a strong pharyngeal or tongue dorsal gesture

• Some speakers have lost any obvious anterior gesture in coda

• Anterior gestures, if present, include retroflex and bunched types of /r/

• This is socially stratified– There should be intra-speaker variation too– How categorical are these variations?

• We need representative dynamic data

Dutch background

• Large sociolinguistic, phonetic and phonological survey of Dutch (van Hout, Zonneveld and Van der Velde)– 400 subjects in multiple locations in

Netherlands

• Some speakers have uvular trill/fricative /r/ in onset, and an anterior approximant in codas– What is going on articulatorily?– What is the inter-speaker sub-variation like?

Dutch study

• Subjects– 10 – all in Edinburgh– Post-screened down to 4 anterior /r/ users

• Materials and protocol– Picture naming (n < 30)– Real words, near minimal pairs: /ir/ /ur/ /ar/– Singleton /r/ and cluster /r/ and /r/-less – 3 reps

• Feedback– Unaware of focus on /r/

Dutch study

• Target – it’s a multi gestural thing– How do we choose the right frame for /r/?– Using acoustics needs good synchronisation– Using the images themselves is circular– Intergestural timing at 25Hz?

• Dynamics– How to characterise?

• Acoustics– Same sort of questions – target & dynamics– Final devoicing…

Boer MS – point is red at end of voice – tip down

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Mier 1 RB

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So far

• Visual inspection of raw images or dynamic spline diagrams– Two retroflexers (RB VDL)– Two bunchers (MS VDB)

Next

• Acoustic identification of an r phase– Midpoint spline can be extracted – No discrimination of voiced or voiceless– Identification of single “max rhotic” is similar

• Acoustic analysis– Steady-state V + transition + r-phase– Location of end of voicing– F2 & F3 of voiced (usually) r target if obvious

MS bunched mainly voiced

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VDL… real non-rhotic vowels for comparison

boer vs. koe

mier vs. riem

schaar vs. sla350 400 450 500 550 600 650

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Dutch summary

• 4 speakers with anterior coda /r/– Two retroflex – Two bunch

• One of the retroflex speakers is gradiently vocalising– Timing the /r/ late before pause– But some long domain cues in vowel quality

and consonant variation– RB has strong transitions too rather than

steady state but ?? sounds more rhotic• Interesting to look at following C…

Overall summary

• Dutch anterior /r/ has various flavours– Retroflex– Non-retroflex– Weakened and late pre-pausal gesture

• Glasgow /r/ comes in various flavours– Pharyngeal approximant observed– Breaking taking over from “rhoticity”

• Strong phonetic effects– Vulnerable non-standard speech– Socially-stratified qualitative UTI is T.o.C.

Conclusions, implications

• Weakening of final /r/ is flexible– Multiple articulators provide lots of options– Strength and timing are affected– Effects can be gradient and/or categorical – Acoustic effects appear complex– Phonological contrasts need not be affected

• Small (?) sub-phonemic effects, change, and variation go hand-in-hand

• Fine detail and structured variation are in the grammar

Methodology – field solution

• Splines and edges lose a lot of info– Relative to MRI X-ray etc– Relative to ultrasound images

• Qualitative analysis of images usefully augments impressionistic transcription

• This can be done live and/or from tapes made in the field

• Small amounts of data from large numbers of subjects is standard practice

Methodology: lab solution #1

• Dedicated hardware + software in the lab

Ultrasound e lem ent echo response buffe rs(one pe r e lem ent) f illed cyc lic ly f rom le f t to right

Matrix of raw data

time stamped at headline sample rate (100Hz)

Image processing

Audio etc

Time stamped

PC buffer & files

• High speed, synchronised, clean images• Integrated analysis (spline fit, export etc)

Start

Methodology: lab solution #2

• Multichannel backbone (incl 200Hz EPG)• Funding application submitted

– 100Hz synchronised machine (+ EPG)– Multichannel developments (EMA, VICON)

• Helmet improvements• Also, funding application submitted for

ultrafest 5 (2007)

Holiday report

• Excellent!

Demo of lab data collection

Slide 8AA