Measuring and plotting vowels

David Deterding, December 2006

Data

For measuring the monophthong vowels of English, the Wolf passage can be used (Deterding 2006)

The Boy who Cried Wolf

There was once a poor shepherd boy who used to watch his flocks in the fields next to a dark forest near the foot of a mountain. One hot afternoon, he thought up a good plan to get some company for himself and also have a little fun. Raising his fist in the air, he ran down to the village shouting "Wolf, Wolf." As soon as they heard him, the villagers all rushed from their homes, full of concern for his safety, and two of his cousins even stayed with him for a short while. This gave the boy so much pleasure that a few days later he tried exactly the same trick again, and once more he was successful. However, not long after, a wolf that had just escaped from the zoo was looking for a change from its usual diet of chicken and duck. So, overcoming its fear of being shot, it actually did come out from the forest and began to threaten the sheep. Racing down to the village, the boy of course cried out even louder than before. Unfortunately, as all the villagers were convinced that he was trying to fool them a third time, they told him, "Go away and donít bother us again." And so the wolf had a feast.

Measurement

Use of PRAAT software (Boersma & Weenink 2006) is recommended for the measurement of the first two formants of vowels.

The following guidelines are suggested (Deterding 1997)

The following words from the Wolf passage can be used:

Vowel    Words
   /i:/sheep, even, feast
   /ɪ/little, fist, this, chicken, did, convinced
   /e/shepherd, next, get, pleasure, successful
   /æ/plan, exaclty, actually, began, had
   /ʌ/up, company, fun, cousins, much. ducl, come
   /ɑ:/dark, afternoon, after
   /ɒ/flocks, hot, not, shot, bother
   /ɔ:/thought, short, more, course, before, unfortunately
   /ʊ/foot, good, looking
   /u:/afternoon, soon, two, zoo
   /ɜ:/heard, concern, third

BUT:

Plotting

If you use the following Excel file for plotting the vowels, you can either enter the formants of each vowel separately, with one worksheet for each vowel of RP British English, or you can enter the final values directly into the 'summary' worksheet. (The Wolf-RP file has been done that way.)

The formant values (in Hz) are then converted to the auditory Bark scale using the formula of Zwicker and Terhardt (1980) and plotted on a chart of F1 (on the y-axis) against F2 (on the x-axis), to give a representation of the open-close and front-back quality of the vowels.

empty template

Wolf RP values   B1   B2   B3   (from Deterding 2006)

References

Boersma, P. & Weenink, D. (2006) Doing phonetics by computer. Accessed on 7 December 2006 from http://www.fon.hum.uva.nl/praat/

Deterding, D. (1997). The Formants of Monophthong Vowels in Standard Southern British English Pronunciation. Journal of the International Phonetic Association, 27, 47-55. (For vowel measurements, click here.)

Deterding, D. (2006). The North Wind versus a Wolf: short texts for the description and measurement of English pronunciation. Journal of the International Phonetic Association, 36(2), 187-196.

Zwicker, E., & Terhardt, E. (1980). Analytical expression for critical-band rate and critical bandwidth as a function of frequency. Journal of the Acoustical Society of America, 68(5), 1523-1525.