Å®ÉúСÊÓƵ

Sin is desirable. At least, an Italian slimmer might appear to be saying
so if their pronunciation of the English word ‘thin’ is not quite up to
scratch. But an interactive computer tutor should soon be helping language
students to turn away from linguistic sin and pronounce words properly.

At the heart of the tutor is speech-recognition circuitry that plugs
into a personal computer. Software running on the PC offers the student
words and phrases to speak, as in a language laboratory. But in addition,
it analyses students’ mistakes in pronunciation, and shows them how to improve
it.

Steve Hiller, of the Centre for Speech Technology Research at the University
of Edinburgh, has been working on the tutor for two years with partners
in France and Italy and at the publisher Berlitz. He says the tutor breaks
down speech into phonemes, the basic phonetic units of language. There are
44 phonemes in standard English.

The student chooses whether to practise vowels, consonants, rhythm or
intonation. The computer then displays about ten words on the screen for
the student to pronounce. As well as knowing what the student should have
said, it has a database of likely mispronunciations – such as ‘pet’ instead
of ‘pit’ – which cuts down the number of deductions it has to make.

Once the computer has decided what the student said, it compares the
pronunciation with the same word pronounced by native speakers, stored on
a CD. If the student is practising vowels, the computer displays a target
in the middle of the screen, and a dot to show how close the vowel was to
ideal. The student can experiment with the words to try to hit the target,
which represents the average pronunciation of 11 native English speakers.

For consonants such as ‘th’ the tutor shows the student how to move
from the ‘s’ or ‘t’ sound they make naturally, towards a better sound –
for example, by opening the gap between their tongue and palette. For rhythm
it analyses the stress given to each syllable of a word. ‘If you’re learning
English, you have to make some sounds weaker than others,’ says Hiller.

The centre is about to start a two-year project adapting the tutor for
deaf people. It hopes to improve the speech of patients who have a cochlear
implant and of people who were born deaf.