How we speak and breath....where does stress come from?

Here is an activity from Piers Messum and Roslyn Young. They are both members of a special interest group that discuss issues relating to pronunciation. I have added it to our blog as I think it is interesting and relevant for trainee teachers.

The issue that they have been discussing in general is whether it is a good idea to teach students pronunciation with a 'listen and repeat' model. This is the primary method used in EFL throughout the world. They question its utility. We will start with the idea of stress and timing.

1 When we speak we're normally unaware of how we control our breath (our

`speech breathing'). But in extreme circumstances, it's more apparent.

Try

saying a nursery rhyme (like `Jack and Jill went up the hill, to fetch a

pail of

water') in a loud whisper. Try saying it after breathing out almost all

of the

air that you can. (It may help to stand up for this exercise.)

a) What can you feel in the muscles around your waist?

Now go back to normal breathing and make a string of short /s/ sounds at

different rates. 4 per second, 2 per second and 1 per second.

b) What can you feel in each case in the muscles around your waist?

http://uk.groups.yahoo.com/group/iatefl_pronsig/message/916

The idea behind the first exercise was for people to become a bit more

aware of what they do with their respiratory systems during speech.

Technically, this is known as speech breathing (SB), although the name

is a bit imprecise: we're only really concerned with the control of

expiratory ventilation rather than breathing as a whole.

When we speak under normal conditions, we use voluntary muscular

activity to inhale. Pulling down the diaphragm and expanding the ribcage

opens up our lungs, and air flows in. The muscular activity stretches

the stiff, elastic tissue in our chest walls and as we decrease the

voluntary effort this tissue creates pressure inside us as it starts to

recoil. The situation is not dissimilar to a balloon, where the elastic

skin compresses the air inside.

The pressure this creates is more or less sufficient to drive the vocal

folds and create other sounds sources in the mouth (explosions for /p/

and /t/ etc). As we `deflate' we add a bit of pressure through

voluntary muscular activity, but for normal speech we really don't

need to do much that is active with our respiratory systems. There's

a constant pressure under our vocal folds, and all the interesting

things in speech happen from the vocal folds upwards.

This changes under extreme conditions, or when we don't speak

normally. If you tried to say a train of /s/ sounds at different rates,

you probably found that at 4 per second your SB was as it is during

normal speech. But at 1 per second, you were actively compressing

yourself for each sound, and relaxing between sounds. Let's call

that a pulsatile style of SB, since you were breathing out in pulses.

Clearly your SB can be either `smooth' or `pulsatile'

even if it is normally smooth.

This is leading up to a discussion of stress. How do speakers create

routine (rather than emphatic) prominence on some syllables in English?

Among phoneticians, there's disagreement about this and disagreement

in the data. Traditionally, phoneticians said that speakers put more

respiratory system effort into stressed syllables. Some data from the

1970's challenged this, and now there are people who believe that

stress is largely created by a vocal fold adjustment (more tension means

a louder signal) plus lengthening of the syllable, while others think

that it is caused by SB pulsatility which leads to greater loudness and

length automatically.

This affects us as teachers, because it has implications for how we

should teach stress. If stress is no more than greater loudness and

length, we might be best teaching it by getting students to copy

acoustic models.

But if it involves more effort being made by the respiratory system, we

should probably start with this, and get the extra loudness and length

as a by-product of the correct actions being made by the learner.

The extra information which, we think, resolves this dilemma is

something that phoneticians have paid no attention to: the SB of

English-speaking children during the period when they learn to stress

syllables. I looked at this as part of my PhD research, and it turns out

be very significant.

Children have compliant, floppy tissue in their chest walls, not stiff

tissue. So when they breathe in and stretch this tissue there is very

little pressure created by its weak tendency to recoil. If an

adult's lungs are like an inflated balloon at the end of

inspiration, a child's is like an inflated paper bag: full of air,

but not pressurised.

Also, children can't make syllables louder just by tweaking their

vocal folds ( in the way that adults can). They have to increase their

respiratory drive for greater loudness.

So for children learning English, stress has to be the result of

pulsatile SB activity.They are making more effort on every prominent

syllable than on other ones. Stress is something they do with their

respiratory systems and larynx in combination, not just an acoustic

effect they copy with a small adjustment of their vocal folds.

This post would get very long if I went into more detail about this now,

and I think it would be better to see if what I have written so far is

clear to everyone and what questions and thoughts, if any, it

precipitates before we go any further.

The proposal, though, is that stress can and should be taught

non-imitatively: by getting students to do something active with their

respiratory systems for a stressed syllable, and for the result to be

louder and longer as a result of this. Concurrent activities like using

some other part of the body in synchrony with the stressing may be

helpful, but in this case let's get to the core of the matter and

help students to make stress in as `natural' a way as possible:

with their respiratory systems, as phoneticians in the past always used

to recommend.

Piers Messum