For those of you interested in the phonology of Mandan, here's a summary of a presentation I recently sat in on.
Jonina Torres presented
information about the way Mandan, a Siouan language spoken in North
Dakota, differentiates its vowels. She had analyzed a recording of a
Mandan speaker to see how the vowels varied in duration. Mandan
appears to differentiate vowels in both length and nasalization. The
inventory Torres investigaged is /a, a:, ã, ã:, e, e:, i, i:, ĩ,
ĩ:, u, u:, ũ, ũ:, o, o:/.
Using a piece of
software called Praat, she looked at sonograms and blocked off each
vowel for duration. For the most part, short vowels were held for
about 0.1s and long vowels were held for 0.2s. This doesn't surprise
me given the describers long and short. Torres found two pairs that
did not fit the pattern. The first is the distinction between /ã/
and /ã:/. The short /ã/ was held for about 0.25s, and the long /ã:/
was held for about 0.15s. This is odd, since the “short” vowel
was in fact longer than the “long” vowel. The other surprise in
her data was the variance between /ũ/ and /ũ:/. Short /ũ/ was held
for 0.1s, which is in line with the other short vowels. On the other
hand long /ũ:/ was held for 0.5s, which was more than twice as long
as all the other long vowels, save /ã:/. Concluding, Torres
suspected that these variations might be evened out if she sampled a
larger data set.