Vowel Space

NOTE:Examples on this website involving Klatt synthesis are currently not working. We are aware of the problem and will fix it as soon as we can.


Most (not all) English vowels are identified acoustically by the frequencies of their first two formants. The diagram above plots the locations of 9 vowels in the two-dimensional space. You can click on any vowel symbol in the figure to hear the synthetic vowel generated by setting F1 and F2 to the coordinate values of the symbol. These vowels are supposed to sound like: The F1,F2 values for these examples were taken from the classic study of American English vowels by Peterson and Barney (1952). A recent replication of the Peterson and Barney study (Hillenbrand, et al., 1995) does not completely agree with the average values Peterson and Barney found. This is most obviously the case for the vowels E and @. This may be because of differences in measurement methods, or because @ vowels have shifted slightly in the last 40 years, or perhaps other factors are involved. Please read about this in the handout of the Hillenbrand, et al. (1995) paper.

Task 1

Listen to each of the vowels in this figure. None sound terribly natural, but some are better exemplars than others of the vowel you would expect to hear. Rank order these 9 vowels from best exemplar of category to poorest exemplar. We'll compare results in class. (Note that ties are allowed)

Task 2

For the vowel you feel is the poorest exemplar of the set, use the simple vowel interface to experiment with changes in F1 and F2 to make a vowel that sounds like a better exemplar to you. Save the F1 and F2 values you used.

Task 3

These vowels should sound like they were produced by a male talker. Use the simple vowel interface to make vowels which sound like they were produced by a female talker. Use 220 as the F0 value for this. Write down the F1 and F2 values you select for each vowel and we'll compare results in class.

References

Hillenbrand, J., Getty, L.A., Clark, M.J., Wheeler, k. (1995). Acoustic
    characteristics of American English vowels. J. Acoust. Soc. Am., 
    97, 3099-3111.

Peterson, G.E., and Barney, H.L., (1952). Control methods used in a
    study of the vowels. J. Acoust. Soc. Am. 24, 175-184.


All text and graphics unless otherwise specified by H. Timothy Bunnell, Ph.D
bunnell@asel.udel.edu

Last Modified: February 25, 1996 (htb).