Showing variation of formants of [i:] with context
by Bob Cunningham
These plots were generated to evaluate an assertion that during the pronunciation
of [i:], the tongue moves front to back and then returns to its original position in
the front part of the mouth.
Note that in "reef", "plebe", and "green, the second formant rises in frequency
during the pronunciation of the vowel. Greater separation of first and second
formants corresponds to moving the tongue farther front.
In contrast, the distance between the formants of "real" decreases slightly
during the pronunciation of the vowel, because the frequency of F1 rises
slightly. The rising F1 suggests that the tongue is moving slightly lower.
None of the vowel's formants suggest that there is a noticeable backing then
fronting of the tongue. The rise of F2 during the beginning of the
vowel in "real" seems to correspond to the end of the pronunciation of "r"; the
fall at the end, to the beginning of "l".
The principal message
carried by the plots is that it's hard to generalize about tongue motion during the
pronunciation of a given vowel. A lot depends upon what the articulatory organs are
doing before and after the vowel.