Using Ultrasound Technology to Improve Tense/Lax Distinctions

in ESL LearnersBryan Meadows, Gwanhi Yun,

Diana Archangeli, Jeff Mielke, and Beth Lukes

University of Arizona

Introduction / Background of Study

• (1) Current situation in the FL classroom– Little comparative attention to pronunciation– A major challenge is the necessary reliance on the

student’s perception

• (2) Necessity for better teaching materials– L2 perception is difficult for learners– L2 production is also challenging– Current materials can be improved

• (3) ELL student campus survey returned positive reactions to ultrasound.

The English tense/lax distinction

The vowel /I/The vowel /i/

The Situation for Korean Speakers Learning English

• Tongue Height and Tongue Root Advancement = most important differences between /i/ and /I/

• Those differences do not coincide with phonemic boundaries found in Korean = same vowel

• Perception (and production) of the tense/lax distinction can be difficult

Goals and hypothesis

• Goals – Develop instructional materials that will aid L2 production of

tense/lax distinction in English high vowels by Korean speakers– Ascertain if the access to ultrasound technology contributes to

L2 development

• Hypothesis – Subjects who interact with the ultrasound technology will exhibit

an improvement in production over those subjects who• (a) have access to ultrasound images but not to images of their own

production, and • (b) receive no access to ultrasound imagery at all during the

treatment sessions.

Pilot Study

Subjects

• Current ESL students on University of Arizona campus

• Majority have less than one-year of experience in the United States

• Native Korean speakers (n=11)

Procedure

• Pre-Treatment Data Collection

• Treatment Sessions (3)

• Post-Treatment Data Collection

Pre- and Post-Treatment Data Collection

• Perception Data Collection– Audio samples of words (same speaker)– Hear sound and choose between two minimal-pair items on paper– Perception task evaluated immediately by experimenter

• Production Data Collection– Same item set—read words sequentially– Produce into microphone and record (audio and ultrasound)– Production task evaluated later by three native English speakers

Samples from Perception and Production Data Collections

win weancheek chickheat hitkeen kinmeet mittpeek pickreap ripseat sitsheep shipteen tin

Treatment Sessions• Subjects divided into 3 groups

– Group One = Full access to Ultrasound• Still and moving images• On-line access to their own production

– Group Two = Restricted access to Ultrasound• Ultrasound images replaced with hand-drawn

illustrations• No access to their own production

– Group Three = No access to Ultrasound• No access to any imagery• No access to self-production

Treatment Group Characteristics (summary)

Group One

Group Two

Group Three

English Model Sounds

English Ultrasound Video

English Ultrasound Images ½

Ultrasound Images of Model Korean ESL Learner

½

Access to Own Production Via Ultrasound

Screen Shots

• What did the English lessons look like?

Group One Sample

Group One Sample

Group One Sample

Group One Sample

Group Two Sample

Group Two Sample

Group Two Sample

Pilot Results

• Pilot experiment did not produce immediate results.

• A step back—discriminatory behavior– Consider statistical chance (50%)– Move to either extreme reflects the subject

making a distinction

• Revised question: Are subjects beginning to make a high-front vowel distinction?

Pilot Results: Percentage Change in Discriminatory Behavior

Group One

Group Two

Group Three

Change in Discriminatory Behavior (PERCEPTION)

23% 18% 13%

Change in Discriminatory Behavior (PRODUCTION)

3% 10% 5%

Scores reflect a subject’s move away from chance (50%) in either direction = ‘noticing’

Individual Success Stories

• Subject 9 Production (Group 1):– 64% native-like attainment pre-treatment– 71% native-like attainment post-treatment– 7% increase in native-like discriminatory behavior

• Subject 2 Production (Group 2):– 61% native-like attainment pre-treatment– 76% native-like attainment post-treatment– 15% increase in native-like discriminatory behavior

• Subject 1 Perception (Group 1):– 81% discrimination accuracy pre-treatment– 30% discrimination accuracy post-treatment– 51% change in discriminatory behavior

Conclusions / Implications

• Immediate results from Ultrasound unattainable.– Initial study which held for many variables.– Time and training were an issue.

• Student-Instructor interaction is likely a missing key component.

• Future studies being considered:– Classroom comparison– Explore further English distinctions (L / R)– Real-time palate imagery will aid future experiments– Experiment with different variables