Consonants I

Compared to vowels, all consonants are made with a greater degree of constriction in the vocal tract. This is true of even the most vowel-like consonants /w/ /j/ /r/ and /l/. The bilabial approximant /w/ is, in articulation, an extreme /u/ and the palatal approximant /j/ is similarly, like an extreme /i/. Since these consonants are most like the vowels we have already been studying, we will begin study of consonants by looking closely at /w/, /j/, /r/, and /l/. We will synthesize these segments first in isolation, and then as the initial consoants of CV syllables.

Given that /w/ is /u/-like, but with more closed (extreme) articulation, it is not surprising that its formant strucutre is similar to, but more extreme than that of /u/. The formant strucutre of /j/ is a more extreme version of /i/, and /r/ is similar to the /ER/ vowel that is central but with a low F3. The lateral approximant /l/ also has features of a central vowel, but unlike /r/ does not have a low F3. As we will see, /l/ is the most difficult of the approximants to synthesize in stationary isolated form.

More specifically, the formant structure measured from examples of uttered speech for each of these consonants is given in the following table:

SegmentF1F2F3
/w/2507502500
/r/3006501200
/l/45011502600
/j/30024502600

Task 1

Use the vowel interface to synthesize stationary copies of each of the four approximant consonants w, r, l, j. Start with the values for F1, F2, and F3 in the table below, but try adjusting the values (vary the formant values to see if you can find a better sounding example for each consonant. Optionally, if you believe you have found a *good* example of any of these consonants, send me the formant values and F0 you used.

Task 2

Now, let's use the general synthesizer interface to produce CV syllables begining with each of the consonants and ending with the vowel /ae/. An example script which produces the syllable /rae/ is given here. Copy and use this as a template and change the formant values to produce each of the four approximant consonants. Try varying both the formant values of the consonant and the transition durations between the steady state of the consonant and the vowel to improve the quality of the synthetic CV. When you have found good examples of each CV, send them to me via email. 
*
* /rae/ template
*
TIME = 000; F1=350; F2=650; F3=1200; F0=120; AV=48
TIME +  40; F1=350; F2=650; F3=1200; AV=72
TIME +  60; F1=650; F2=1750; F3=2500; AV=72
TIME = 400; F1=650; F2=1750; F3=2500; F0=90; AV=72
TIME + 30; AV=0
END
All text and graphics unless otherwise specified by H. Timothy Bunnell, Ph.D
bunnell@asel.udel.edu
Last Modified: March 24, 1999 (htb).