Using Phonetics to Teach Phonology

Francoise and I have been working on the second edition of our book for some time now and the book is finally in the production stage – counting down to a December 2016 release date. One of the decisions we have had to make is whether to keep all the figures that were in the first edition – we must pay the copyright holders (note: not the authors!) in order to gain the right to reproduce all those figures and tables in our book. It is a difficult decision for each and every figure given that the costs vary from approximately $100 to $1000 per figure and there are 99 of them in the book!

Consider the figure shown at the bottom of this post – it illustrates data from some research by Goffman and Malin (1999) in which adults and children produced nonsense words with either a trochaic stress pattern (strong-weak) or an iambic stress-pattern (weak-strong). Kinematic tracings of lower lip movements are shown. The surprise was that the children modulated the stress pattern of the iambic words in a fairly adult-like manner, albeit with less consistency than the adults. The children did not modulate the stress pattern of the trochaic word, producing it like a spondee, with equal stress on both syllables, which was an unexpectedly immature pattern. Why did I choose to keep this figure in a book on phonology? Surely the whole point of phonology is to convert speech to an abstract form like this: [ˈpʌpəp] and [pəˈpʌp]? In the end I decided that I wanted to keep it because I so much want my students to see it – it encapsulates so many primary themes in our book, as follows:

  1. Basic concepts are essential to understand, and for multilingual students in particular, the figure provides a beautiful visual representation of trochee, spondee and iamb that is much more effective than a string of phonetic symbols.
  2. What you get is not always what you hear! If you were to transcribe the child saying the word “puppet” with the kinematics shown in the lower left quadrant of the figure, the odds are that you would produce [ˈpʌpət] which would represent what you expect to hear rather than exactly what the child said. I spend quite a bit of time talking about the limits of phonetic transcription in the first chapter of the book.
  3. The development of prosody is fundamental to the development of phonology: prosodic frames – word templates made up of syllable shapes and stress patterns that are characteristic of ambient language – emerge early and support the acquisition of phonemes. These two levels of the phonological hierarchy are intimately interconnected – it really is time to stop teaching linear phonology.
  4. Phonology is fully dependent upon phonetics – you cannot understand phonological development without understanding the articulatory and perceptual substrates.
  5. Having said that, it is not true that phonological development is determined by maturation of the motor system. If it were, the trochaic pattern would emerge first, before the iambic stress pattern, whereas the reverse is shown in the figure. This demonstration can be the trigger for an interesting discussion of competing approaches to intervention.
  6. The figure is a beautiful illustration of the operation of lexical contrast. Why does the child learn to modulate the strong-strong stress pattern to produce a weak-strong iamb before properly mastering the (for English) canonical strong-weak pattern? Because they must do that in order to produce a contrast between these two word templates in the minds of the listener.
  7. The figure is a lovely illustration of how phonology emerges from the dynamic interplay of phonetic, semantic, and social factors with a dynamic systems approach to development being a coherent thread throughout the book.

The thing about a book however is I can only build possibilities into it – the teaching and the learning is constrained by the imagination of the teachers and the learners. I don’t know how many readers will discover in a paragraph on the development of “interarticulator coordination” a plethora of important messages about the development of phonology.

Figure 3-7

Figure 3–7. Time and amplitude normalized kinematic tracings of displacement of the lower lip during productions of the nonsense words [ˈpʌpəp] (left) and [pəˈpʌp] (right), recorded from an adult (top) and child (bottom). The corresponding spatiotemporal indexes for the repeat productions shown are: (A) adult trochee STI = 8.56, (B) adult iamb STI = 8.99, (C) child trochee STI =18.15, and (D) child iamb STI = 14.24. Adapted from Goffman & Malin (1999). Metrical effects on speech movements in children and adults. Journal of Speech, Language, and Hearing Research, 42, Figure 5, p. 1009. Used with permission of the American Speech-Hearing-Language Association.

References

Rvachew, S., & Brosseau-Lapré, F. (2018). Developmental Phonological Disorders: Foundations of Clinical Practice (Second Edition). San Diego, CA: Plural Publishing. http://pluralpublishing.com/publication_dpd2e.htm

Goffman, L., & Malin, C. (1999). Metrical effects on speech movements in children and adults. Journal of Speech, Language and Hearing Research, 42, 1003-1015

(edited on August 26, 2016 to correct copy-right date for DPD2e. The second edition will be released in December 2016)

Acquisition of Fricatives in Icelandic and French

I point out in this blog a recent paper by Bernhardt and colleagues describing fricative production by Icelandic preschoolers with “protracted phonological development”. Icelandic-speaking children with speech problems produced /f,s,θ/ with about 70% accuracy by four years of age. The English-speaking children with speech problems achieved less than 15% accuracy on the single word naming task (those of us who work with those children are not surprised!). Error patterns were different as well (for example, the Icelandic children substituted [t] for /f/ whereas the English children substituted [p] for /f/). The study is a nice reminder of the need for language specific articulation tests for children with intelligibility problems whose first language is not the majority language. There are no universal developmental patterns. Therefore we can be grateful to Sharynne McLeod and the International Working Group on Multilingual Children’s Speech for their great site.

A point of theory in the paper was the failure to support the hypothesis of “higher overall fricative accuracy for English, because English has more fricative types.” This hypothesis was put forward because Edwards, Beckman and Munson concluded that “the more words containing a sound that a child has learned to say, the more practiced the child becomes at recognizing and reproducing the sound abstracted away from the phonological contexts of a few specific words.” One example given is the case of /ð/ in English. I was surprised that an alternative hypothesis, considering the prosodic structure of Icelandic, was not tested. Perhaps the authors didn’t want to attempt this because it is so hard to understand the prosodic structure of Icelandic! I certainly will not try to do this. However I point out that French and Icelandic are characterized by earlier acquisition of fricatives compared to English:

Acq of Fric

Françoise and I have previously pointed out that the prosody of French helps children learn the segments. Several studies now confirm that French-speaking children learn consonants early: they have a complete consonant repertoire at an early age and they master accurate production of the consonants at an early age (compared to English). Furthermore, French-speaking children with speech problems produce more syllable structure and fewer segmental errors (compared to English-speaking children with speech problems). How does the prosody of French explain these findings? French is a syllable timed language with a tendency toward long words made of several syllables having equal stress. The syllables tend to have a simple CV structure even though complex onsets and codas are allowed. The difference between the two languages can be observed in the ratio of consonants to vowels, being 1.6 in French and 2.1 in English.

Recall that when children first learn to speak, they learn to produce “whole words” and not strings of individual segments; these first whole words act as templates for the production of more words. These initial templates are often made up of reduplicated or partially reduplicated syllables. Possibly, if the initial word shape template is easy to learn or construct, more processing power is left over to acquire the segments inside the syllables. Furthermore, simple stressed syllables in French may increase the perceptual salience of those segments. Vihman provides wonderful examples of this process in her very excellent paper on templatic phonology. The French child, Gael, saying words like ‘accroché’ [χʁoʃe] at age 21 months is rather fun to see!

Possibly the same process occurs in Icelandic which has a very particular prosody that may also increase the perceptual salience of postvocalic consonants, fricatives in particular. I will not attempt an explanation, the phonology of Icelandic being quite beyond me, but any explanation for the early acquisition of these phonemes must take the prosodic (word shape) characteristics of early child input into account.

In the meantime some more general points strike me. It is impossible for us as speech-language pathologists or academics to understand the process of speech development without data and it is disheartening how little data there is on these languages. Basic information such as the types and tokens of fricatives that are presented to children in the input across languages is difficult to find. We need to know much more about the prosody of all these languages but prosody receives scandalously little attention compared to, for example, consonants.

We also need to know more about the processes by which children select and construct their early word templates. This requires painstaking small sample detailed longitudinal work and large, large sample laboratory work using creative paradigms, some probably not invented yet. However, all our work is perilously underpowered and underfunded.

Finally we need huge diversity in academia – lots and lots of movement of students across the world, bringing new techniques to new languages. Unfortunately in the past few days, in the aftermath of Brexit, I have encountered many depressing conversations on the internet about the control of borders. Even in the domain of “highly qualified personnel”, some graduates are deemed more worthy than others and we all know where the humanities fall on the ranking! I prefer not to counter this sort of thinking with purely utilitarian arguments, but clearly it is short sighted given the importance of communication and communication disorders. On a more positive note I close by congratulating the excellence of child phonology projects sustained on a wing and a prayer such as the Cross-linguistic Child Phonology Project led by Bernhardt and colleagues and also the Paidologos project led by Edwards and colleagues.

 

References

Bernhardt, B. M., Másdóttir, T., Stemberger, J. P., Leonhardt, L., & Hansson, G. Ó. (2015). Fricative acquisition in English- and Icelandic-speaking preschoolers with protracted phonological development. Clinical Linguistics & Phonetics, 29(8-10), 642-665. doi:10.3109/02699206.2015.1036463

Brosseau-Lapré, F., & Rvachew, S. (2014). Cross-linguistic comparison of speech errors produced by English- and French-speaking preschool age children witih developmental phonological disorders. International Journal of Speech-Language Pathology, 16(2), 98-108.

Edwards, J., Beckman, M. E., & Munson, B. (2015). Frequency effects in phonological acquisition. Journal of Child Language, 42(02), 306-311. doi:doi:10.1017/S0305000914000634

MacLeod, A. A. N., Sutton, A., Trudeau, N., & Thordardottir, E. (2011). The acquisition of consonants in Québec French: A cross-sectional study of preschool aged children. International Journal of Speech-Language Pathology, 13, 93-109.

Rvachew, S., Marquis, A., Brosseau-Lapré, F., Paul, M., Royle, P., & Gonnerman, L. M. (2013). Speech articulation performance of francophone children in the early school years: Norming of the Test de Dépistage Francophone de Phonologie. Clinical Linguistics & Phonetics, 27(12), 950-968. doi:doi:10.3109/02699206.2013.830149

How should we describe substitutions in phonology?

I have just read the very nice paper by Little, Bernhardt & Payne (2014) in the open-access journal CJSLPA. It contains a very nice description of nonlinear phonology followed by an analysis of the speech produced by a child with a rare metabolic condition called “3-methylglutaconic aciduria type I”. I liked the early part of the paper in which the authors discuss nonlinear phonology from two perspectives, optimality theory versus a connectionist modeling approach, because personally I find OT to be a waste of time because it is my opinion that this model is not biologically plausible whereas connectionist modeling (depending on the model of course) can often do a pretty decent job of simulating developmental processes. So I found that part to be interesting. As for the latter part of the paper, I got a bit hung up in the details unfortunately, and one detail in particular was crazy making: The authors described the substitution errors like this:  “Fricatives were deleted or substituted with stops or other fricatives; /ɹ/ was deleted or substituted with [w] (onset), or with a vowel (coda)” (p. 289).

If you are younger than me this may not strike you as strange but it was to me so odd I looked it up and I found a discussion about the usage of the word “substituted” on the on-line Oxford Dictionary which says that the traditional form is “A was substituted for B” but that due to frequent use by sports commentators the form “B was substituted with A” is currently  accepted usage despite the fact that “this can be confusing” (no kidding!). Apparently in chemistry it is common to say “B was substituted by A” which is a form my students in Quebec will use which has always confused the heck out of me.

In phonology, the confusion is particularly acute because of the use of the short form A/B  in both informal and formal written reports to describe children’s speech errors. Recently I was interacting with an SLP who was asking for advice about a child and she described the child’s errors as t/k, d/g. Confusion reigned until it was established that the child’s pattern was backing and not fronting!

So it looks to me that if we have a child who says “keep” /kip/ = [tip], we now have alternative forms of communicating this in the SLP community:

Old fogie way:

  • Long form: The child substituted [t] for /k/.
  • Short form: t/k substitution

New fangled way:

  • Long form: The child substituted /k/ with [t]. (The child substituted /k/ by [t].)
  • Short form: k/t substitution

This means that we have a serious problem with confusion in written reports when the short form is used. In oral reporting there is still a risk of confusion because we do not typically transmit the square brackets and slashes when we are speaking.

So, solutions, anyone?