Guidelines for promoting intelligibility

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Guidelines for promoting intelligibility

• John M. Levis
• Iowa State University
• jlevis_at_iastate.edu

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Why I am exploring this topic?

• Intelligibility is widely agreed to be the most
  important goal for spoken language development,
  for both listening and speaking
• It is the most important goal for ESL settings
  and for non-ESL settings (both where NNSs will
  interact with NSs and where they interact
  primarily with other NNSs)
• Intelligibility is a moving target, depending on
  the interlocutors, situation, register, and other
  elements of context. Thus, context-sensitive
  principles are needed to make decisions.

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Overview of talk

• What is intelligibility?
• Why is it important?
• What is thought to promote intelligibility?
• The segmentals/suprasegmentals debate
• Guidelines for promoting intelligibility
• Nuanced intelligibility Recommendations

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What is intelligibility?

• General definition
• Intelligibility may be broadly defined as the
  extent to which a speakers message is actually
  understood by a listener (Munro Derwing 1999,
  p. 289)
• This broad definition implies at least two
  different types of understanding
• Successfully identifying words
• Understanding a speakers intended meaning

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Successfully identifying words

• Intelligibility (technical definition)
• The ability of listeners to accurately decode
  individual words in the stream of speech
• or, The ability of a speaker to say words in such
  a way that listeners can decode them
• Pronunciation deviations do not necessarily
  impair the ability to decode, e.g.
• Dialect pronunciations
• English as a Lingua Franca (Nonnative) speaker
  pronunciations

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Understanding intended meanings

• Comprehensibility (two definitions)
• The accuracy with which a speakers intended
  meaning is perceived (this implies a way to
  measure comprehension)
• Hahn (2004)
• The perception of how easy it is to understand a
  speaker (this implies a more global view of
  comprehension that trusts listeners intuitions)
• Derwing and Munro Munro Derwing (various
  references)

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Why is this important?

• Teaching for intelligibility/comprehensibility
  implies a principle of differential importance
• Some pronunciation errors are more likely to
  affect understanding than others
• Some pronunciation teaching topics should be
  emphasized while others should not
• Theres a practical reason as well. It is rare
  to have courses devoted to pronunciation
  instruction. So we need to make changes quickly
  and effectively.
• Triage (Judy Gilbert)

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Native-like accents and intelligibility

• Intelligibility assumes that native-like
  pronunciation is not an important goal Rather,
  its important to be understandable even if
  accented. Why not a native accent?
• It doesnt seem to be possible for most learners
• Its not necessary (unless youre a spy)
• Language proficiency does not depend upon having
  a native-like accent
• Everyone, even native speakers, has an accent.
  Being native-like usually means privileging one
  accent above other appropriate accents.

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What promotes intelligibility?Some proposals

• A focus on suprasegmentals
• a short-term pronunciation course should focus
  first and foremost on suprasegmentals, as they
  have the greatest impact on the comprehensibility
  of learners English (McNerny Mendelsohn,
  1992, 186)

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• An emphasis on the big picture
• The Zoom Principle
• A pronunciation syllabus should begin with the
  widest possible focus i.e., general speaking
  habits and move gradually in on specific
  problems (Firth 1992, 173)

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• Attending to errors that affect NNS understanding
• Most speakers of English in the world are NNSs
  who speak English with other NNSs.
• Multiple Englishes imply a need for an
  internationally understandable norm
• if we are to provide appropriate pedagogic
  proposals for EIL pronunciation, then these must
  be linked directly to relevant descriptions of
  NNS speechin terms of what constitutes optimum
  productive competence and what learners need to
  be able to comprehend (Jenkins, 2002, 84)

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Segmentals vs. Suprasegmentals

• The traditional debate
• Suprasegmentals are more likely to promote
  comprehensibility
• But, segmentals are obviously important
• But, suprasegmentals are more likely to reveal
  common problems across a range of first language
  backgrounds
• But.

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• Why the debate is not useful
• You cant have one without the other
• Rhythmic structure (a suprasegmental) and vowel
  quality (a segmental) are interdependent, e.g.
  récord vs. recórd
• Rhythmic structure and consonant clarity are
  closely connected (e.g., aspiration of initial
  stops rappél vs. rápid deletion of /h/ in
  unstressed syllables Did he do it? are affected
  by stress patterns

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• Differential importance applies within categories
  as well as across categories
• Final consonant errors in Vietnamese-accented
  English impair listener understanding more than
  initial consonant errors (Zielinski, 2006)

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• Field (2005) studied listeners ability to
  understand 2-syllable word stress errors with and
  without changes in vowel quality. He found that
  there is a significant decrement in
  intelligibility when stress is shifted to an
  unstressed syllable without an accompanying
  change in vowel quality (p. 414). When the
  stress shift was accompanied by a change in vowel
  quality (from weak to full) the loss of
  intelligibility was considerably less marked (p.
  415)

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Seven Guidelines for teaching for intelligibility

• Derwing Munro (2005) call for decisions about
  pronunciation teaching to be based on research.
  This is important, but as they admit, there is
  not enough research yet to base all decisions on
  it. So,
• Some of my guidelines come from research
• Some come from practice
• These are offered in no particular order of
  importance and show some overlap

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Seven guidelines

• Functional load
• Frequency
• Potential for penalty
• Probability of offense
• Lexical importance
• Processing constraints
• Learnability

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Guideline 1 Functional load

• Functional load is a measure of the work two
  phonemes do in keeping utterances apart (King,
  1967, as cited in Munro Derwing 2006, 522).
  Functional load is measured partly by
• of initial minimal pairs two sounds have
• of final minimal pairs two sounds have
• Likelihood that the distinction is enforced in
  all varieties of English

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Munro Derwing 2006

• Tested NS subjects listening to sentences with
  high and low functional load errors
• High functional load errors
• /l/-/n/ (light-night), /s/-/?/(sell-shell),
  /d/-/z/ (ride-rise)
• Low functional load errors
• /ð/-/d/ (then-den), /?/-/f/ (three-free)
• Subjects rated accentedness and comprehensibility
  of the sentences
• Accentedness (on a scale of 1-9)
• Perceived comprehensibility (on a scale of 1-9)

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• Low FL errors and accentedness
• the presence of one, two, or three low FL errors
  resulted in significantly worse judgments of
  accent than the presence of no errors (527)

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• High FL errors strongly affect comprehensibility
• high FL errors had a significantly greater
  effects on the listeners ratings for
  comprehensibility than did low FL errors. Even
  sentences that contained only one high FL error
  were rated significantly worse for
  comprehensibility than sentences containing three
  low FL errors (527)

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• Conclusions
• Errors in phonemes that carry a high functional
  load are more likely to affect listeners ability
  to understand than are errors with sounds that
  carry a low functional load

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Guideline 2 Frequency

• Base Belief Speech that contains more phonetic
  and phonemic errors will be less understandable
  than speech that contains fewer
• unintelligibilityis the cumulative effect of
  many little departures from the phonetic norms of
  the language. A great many of these may be
  phonemic many others are not. Under certain
  circumstances, any abnormality of speech can
  contribute to unintelligibility
• (Prator Robinett, 1985, xxii)

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Munro Derwing 2006

• There is some evidence for and against this
  concept, again from the previous study on
  functional load
• Low FL errors and frequency
• the presence of one, two, or three low FL errors
  resulted in significantly worse judgments of
  accent than the presence of no errors. However,
  sentences with two or three low FL errors were
  not rated as more accented than sentences that
  contained a single FL error. In other words,
  there was no evidence of a cumulative effect of
  low FL errors on accentedness (527)

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• Frequency of high FL errors and accent
• Althoughthe presence of one or two high FL
  errors led to a significant increase in the
  perception of accentedness over the no-error
  condition, sentences containing two high FL
  errors were rated as significantly more accented
  than sentences containing only one high FL error.
  In other words, a cumulative effect of high FL
  errors was seen (527)

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• Frequency of high FL errors and comprehensibility
• Sentences with one and two high FL errors were
  equally comprehensible
• It may bethat numbers of segmental errors alone
  do not account fully for variability in
  accentedness or comprehensibility. Rather, the
  nature of the errors may affect their
  performance (530)

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Guideline 3 Potential for Penalty

• Certain contexts of use have higher stakes for
  the speaker and listener than others. If youre
  selling in a shop in an area where ethnic shops
  are the norm, your needs for understandable
  pronunciation are lower than if you are a doctor
  or a nurse. Some high stakes areas
• Education (International teaching assistants)
• Health (Medical personnel)
• Translation (Spoken language translators)

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• While this principle is important, it also opens
  the very real possibility of prejudicial
  judgments of speech that have nothing to do with
  being understood
• Rubin (1992)
• Lippi-Green (1997)
• Munro (2003)

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Guideline 4 Probability of offense

• When mispronunciations sound like taboo words
• Beach, sheet, piece (/i/ vs. /I/)
• Taboo sound-alikes can come up in very unexpected
  places
• French class speaking about silverware,
  students were being unresponsive, teacher changed
  to English A fork sounded like fuck!
  Havent you ever had a fuck?
• focus

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• These kinds of mistakes carry the possibility of
  extreme distraction or embarrassment and need to
  be addressed, either by instruction or avoidance
• Taboo sound-alikes fit with a concept related to
  intelligibility/comprehensibility, irritation.
  Irritation can occur whenever a listener finds
  speech understandable but unpleasant for some
  reason, such as type of accent.

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Guideline 5 Lexical importance

• Some words carry key content more than others
  This is especially important in high stakes
  communication contexts.
• Ability to guess meaning from context in reading
  comprehension is impaired when fewer than 95 of
  the words are known. When fewer than 80 of the
  words are known, the ability to understand is
  very low (Nation 1990)
• If these are the figures for reading, where the
  permanent nature of the text is a significant
  help, what must they be for listening?

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• Example International Teaching Assistant
  instruction
• Most ITA training has an emphasis on pronouncing
  key technical vocabulary correctly
• There is also often attention to pronouncing key
  sub-technical vocabulary (words that cut across
  disciplines, such as develop) understandably
• When content is unfamiliar, understanding is
  impaired both by the subject matter and the way
  the content is packaged (the spoken qualities of
  the message)

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Guideline 6 Processing constraints

• Unfamiliar messages will take longer to process
  than will familiar messages
• Familiarity in content
• Familiarity in speech style
• Heard coROLLary in a talk by Wilga Rivers when
  I expected COroLAry It took me 45 seconds to
  unpack the segmentals
• NNS listener perceptions (Jenkins 2002) let
  cars and clay houses)
• NS perceptions (Munro and Derwing)
• Expected mistakes vs. unexpected ones

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• When knowledge of the world (top-down processing)
  and the understanding of the speech details
  (bottom-up processing) do not match, NS listeners
  will first try a top-down interpretation that
  makes sense. If that does not work, they will
  try to process from a bottom-up perspective. Or
  they will give up.
• If there is insufficient knowledge of the world
  (top-down knowledge) then listeners must rely
  more heavily on bottom-up processing.
• There is evidence that L2 learners rely more
  heavily on bottom-up processing than do L1
  learners in their native language

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• When processing constraints interact with
  high-stakes listening where the potential for
  penalty is great, the problems can be enormous
• ITAs teaching in any college field
• Miranda warnings and word frequency

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• Reaction time research
• The work of Anne Cutler and her colleagues (see
  Cutler, Dahan, van Donselaar 1997 for a review)
  consistently shows that unexpected elements in
  speech affect listeners ability to process
  speech
• Other research, such as John Fields study,
  measure the cases where intelligibility is
  entirely lost (2005, p. 415). This kind of
  research is less sensitive to processing demands
  than reaction time research

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• Munro Derwings research shows that loss of
  comprehensibility (where the speakers intended
  meaning does not seem clear) is far more common
  and probably more serious than loss of
  intelligibility (where a word cannot be
  understood). This is likely due to processing
  difficulties.

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Guideline 7 Learnability

• Some features of pronunciation are more learnable
• Jenkins (2002)
• Besides not being a cause of unintelligibility
  in Jenkins data as many pronunciation teachers
  are aware, some of these features seem to be
  unteachable. That is, no matter how much
  classroom time is spent on them, learners do not
  acquire them (97)

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• Some areas not included in Jenkins Lingua Franca
  core (2002)
• /?/ (thank), /ð/ (then), /?/ (will)
• Weak forms, especially the use of /?/ (schwa) in
  words like to, and, from. In EIL, the full
  vowel sounds tend to help rather than hinder
  intelligibility (98)
• Final Pitch movement
• Levis (1999) - Pitch movement differences on
  certain types of grammatical forms (yes-no
  questions) are not important to teach

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Further evidence that some features may not be
learnable

• Pennington and Ellis (2000)
• Recognition tasks for several aspects of
  intonation/stress for Cantonese speakers learning
  English
• Contrastive sentence focus (Is HE driving the
  bus? Vs. Is he driving the bus?)
• Final pitch movement on tags (Hes going, isnt
  he? (rising vs. falling)
• Phrasing (The fight is over, Fred vs. The fight
  is over Fred)
• Internal phrase structure (Shes a lighthouse
  keeper vs. Shes a light housekeeper)

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• Recognition tasks in two conditions When there
  was no previous instruction, and when there was.
• Subjects performed well on recognizing the words
  and grammar of previously heard sentences when
  prosodic form was not tested
• Subjects performed poorly on recognizing
  previously heard sentences if prosodic form was
  included. This was especially so when there was
  not previous explicit focus on form.

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• Training with explicit focus on prosodic form
  increased recognition ability only for
  contrastive sentence focus. The other aspects of
  intonation/stress were not amenable to
  instruction
• Why did only contrastive sentence focus show
  improvement?
• certain aspects of prosody --- such as the
  relatively universal relationship of enhanced
  prosody and marked meaning, as contrasted with
  neutral prosody and unmarked meaning --- can be
  more readily taught than some other more
  language-specific aspects of prosody (p. 387)

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Recommendations

• Take a nuanced view of any target. It is likely
  that all phonological categories include more and
  less important features, e.g.,
• Consonants (Some targets are important, some are
  less so e.g., /l/-/n/ is more critical than
  /?/-/f/ or /ð/-/d/)
• Vowels (phonetic length may be more important
  than phonemic quality Jenkins 2002)

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• Intonation (Not all kinds of intonation are
  likely to be equally important. Sentence focus
  is likely to be important (Hahn 2004 Pennington
  and Ellis 2000) while final intonation,
  especially on certain grammatical structures, is
  much less so (Levis 1999 Pennington and Ellis
  2000)
• Word Stress (e.g., Rightward misstressing
  affected intelligibility more than leftward
  (Field 2005)

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• Distinguish between listening and speaking
• Listening improvement can lead to production
  improvement
• Learning to hear the /l/-/r/ distinction can lead
  to better production for Japanese learners even
  without practice (Bradlow, Pisoni,
  Akahane-Yamada, and Tokhura1997)
• Even when features are not considered learnable
  in normal classroom instruction, teaching the
  feature for reception may be critical for later
  acquisition outside the classroom (Jenkins 2002)
• Building a range of tolerance for understanding
  (listener training) will develop flexibility

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• Recognize that not all learners need to function
  in the same contexts
• Some need to understand and be understood by NS
  interlocutors
• Some need to understand and be understood by NNS
  interlocutors
• There is compelling evidence that ELF i.e.,
  NNS interlocutors engage in communication
  strategies and accommodation processes that may
  conflict with the ways in which NSs typically
  negotiate understanding (Pickering 2006, 227)

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• Recognize that pronunciation is more than
  listening and speaking
• Visual support can be critical
• Body language (e.g., for negation)
• Visual support (e.g., ITAs)
• Circumlocution is useful for any speaker
• Oral spelling or restatement of numbers can
  quickly disambiguate many situations

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What might be our priorities?

• Functional load and Frequency
• Word Stress
• Consonants, including high functional load
  consonants, aspiration and final consonants with
  grammatical meaning
• Vowel lengthening and vowel quality
• Weak forms and fast speech phenomena (for
  listening)
• Potential for penalty, Probability of offense,
  and Lexical importance
• Key vocabulary for speaking needs

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• Processing constraints
• Sentence Focus
• Word Stress
• Weak forms and fast speech phenomena (for
  listening, especially in ESL contexts)
• Learnability
• Sentence focus
• General speaking habits

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• The PowerPoint slides for this talk will be
  available after March 26 at
• jlevis.public.iastate.edu/intelligibility.ppt

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References

• Bradlow, A., Pisoni, D., Akahane-Yamada, R.
  Tokhura, Y. (1997). Training Japanese learners
  to identify /l/ and /r/ IV Some effects of
  perceptual learning on speech production.
  Journal of the Acoustical Society of America,
• Brown, A. (1989). Functional load and the
  teaching of pronunciation. TESOL Quarterly, 22
  (4) 593-606.
• Cutler, A., Dahan, D. van Donselaar, W. (1997).
  Prosody in the comprehension of spoken language
  A literature review. Language and Speech, 40
  (2)141-201.
• Derwing, T. Munro, M. (2005). Second language
  accent and pronunciation teaching A
  research-based approach. TESOL Quarterly, 39
  (3) 379-397.
• Field, J. (2005). Intelligibility and the
  listener. The role of lexical stress. TESOL
  Quarterly, 39 (3) 399-423.
• Firth, S. (1992). Pronunciation syllabus
  design A question of focus. In Teaching
  American English pronunciation, Oxford University
  Press, pp. 173-183.

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• Hahn, L. (2004). Primary stress and
  intelligibility Research to motivate the
  teaching of suprasegmentals. TESOL Quarterly, 38
  (2) 201-223.
• Jenkins, J. (2002). A sociolinguistically-based,
  empirically-researched pronunciation syllabus
  for teaching English as an international
  language. Applied Linguistics, 23 83-103.
• Levis, J. (1999). The intonation and meaning of
  normal yes-no questions. World Englishes, 18
  (3) 373-380.
• Lippi-Green, R. (1997). English with an accent.
  Routledge.
• McNerny, M. Mendelsohn, D. (1992).
  Suprasegmentals in the pronunciation class
  Setting priorities. In Teaching American English
  pronunciation, Oxford University Press, pp.
  185-196.
• Munro, M. (2003). A primer on accent
  discrimination in the Canadian context. TESL
  Canada Journal, 20 (2) 38-51.
• Munro, M. Derwing, T. 1999. Foreign accent,
  comprehensibility, and intelligibility in the
  speech of second language learners. Language
  Learning, 49 (supp. 1) 285-310.
• Munro, M. Derwing, T. (2006). The functional
  load principle in ESL pronunciation instruction
  An exploratory study. System, 34 520-531.

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• Nation, I. S. P. (1990). Teaching and learning
  vocabulary. Newbury House.
• Pennington, M. Ellis, N. (2000). Cantonese
  speakers memory for English sentences with
  prosodic cues. Modern Language Journal, 84 (3)
  372-389.
• Pickering, L. (2006). Current research on
  intelligibility of English as a lingua franca.
  Annual Review of Applied Linguistics, 26
  219-233.
• Prator, C. Robinett, B. 1985. Manual of
  American English pronunciation, 4th ed..
  Rinehart Holt Winston.
• Rubin, D. (1992). Nonlanguage factors affecting
  undergraduates judgments of nonnative
  English-speaking teaching assistants. Research
  in Higher Education, 33 511-531.
• Zielinski, B. (2006). The intelligibility
  cocktail An interaction between listener and
  speaker ingredients. Prospect An Australian
  Journal of TESOL, 21 (1) 22-45.