Ongoing and future research


 

The idea that children learn pronunciation by imitation is deeply embedded in speech science. It's partly true, of course. The pronunciation of most individual words is copied from how the child hears others pronounce them. However, this need only concern the identity and serial order of the speech sounds that make up these words. (The 'ho' 'ri' 'pi' 'lation' of horripilation, for example.) The systemic aspects of their pronunciation need not be copied in this process at all: they will have been learnt previously. That there was any form of imitation during those prior processes of learning is only an assumption, lacking any evidence to support it. Many fundamental problems in the field are resolved by understanding that it is probably wrong, and appreciating what the alternative mechanism is.


Similarly, some aspects of prosody are imitated. But for English-speaking children, if stress-accent is imitated then one does not need to assume that the speech timing phenomena that characterise the language are also learnt by imitation. It is much more likely that they arise as a result of aerodynamics and embodiment.

 

Here are just a few examples of what can now be explained:

  • Is speech an acoustic code reproduced gesturally, or a gestural code made audible?

  • What explains the properties of the tense and lax vowel classes of English? What is the underlying link between tense vowels and diphthongs?

  • Why is the vowel in seat shorter than (the 'same') vowel in seed? Why does the vowel shorten in triplets like ram, ramp, ramped?

  • How can one speaker shadow another with such short latency?

  • Why don't children's patterns of speech development fit what we would expect from a 'copying' mechanism?

  • Is there a ‘rhythm’ to speech production? Is English ‘stress-timed’?

  • Why is pronunciation teaching so ineffective?

This is a very diverse list and it can be extended. But it is not surprising that so much that was mysterious can now be explained. The two alternative mechanisms to imitation that I describe are fundamental to speech production and the effects of us having learned to pronounce in these ways are pervasive.


Rethinking the role of the power supply (speech breathing) and a new understanding of how speech is represented in the brain together have implications for many aspects of speech research.

 

Current projects

 

If it was easy to prove how children learn to pronounce then it would have been done.

 

But of the various proposals in Part 1 of the thesis, some would be reasonably straightforward to test; for example, that respiratory system activity underlies the phenomenon of perceptual-centres (P-centres), as described in s.6.4.1.

 

In Part 2 of the thesis, I propose that the bootstrap to learning to pronounce (i.e. learning to pronounce speech sounds, as opposed to learning to pronounce words) comes from mirroring interactions between mother and child. Ian Howard and I have started to test these proposals through computer modeling and our papers are available on the downloads page.