s - Wyższa Szkoła Filologiczna we Wrocławiu

58
Gabriela Brozbă
These monophthongs are either [e] or [o] depending on the original make-up of
the diphthong. Following the same procedure as in the case of rising diphthongs,
I have analyzed the behavior of the falling diphthongs of the same female
speaker (Mboniswa). Only one of them was realized as a diphthong, while
the other two were realized as monophthongs. Contrary to the expectations, the
NEAR vowel was realized as a diphthong, with the first target vowel a bit raised
than the corresponding monophthong of the same subject. Actually, a slightly
different method was used to plot the gliding point of this diphthong: the values
of the second formant were plot against the values of the first formant by deduction.
As can be seen in Figure 3, the NEAR diphthong descends from the first
target time (red dot), which is a close front high vowel, towards the second target
time (blue dot), which is a mid-open front vowel.
F2-Backness (Hz)
2500 2400 2300 2200 2100 2000 1900 1800 1700 1600 1500 1400 1300 1200 1100 1000
i
NEAR
e
ǫ
SQUARE
o
CURE
900
200
300
400
500
600
700
800
900
1000
F1-Height (Hz)
Figure 3. Realization of BSAE falling diphthongs (Mboniswa)
The CURE vowel was clearly realized as a monophthong, more precisely as
the mid back rounded tense vowel [o] because its F1 (397 Hz) is much lower
than the F1 of the open-mid back rounded vowel identified among the monophthongs
of the same female subject, whose mean value varies between 431
Hz and 470 Hz. The SQUARE vowel was much more problematic. If one takes a
look at the spectrogram in Figure 4, one can notice that in the area delimited by
the white elliptical shape the second formant is missing.
However, since diphthongs imply movement of both formants from the start
vowel target position towards the final vowel target position, I have used the
first formant alone to establish whether the sound at issue behaves as a monophthong
or as a diphthong. The portion which delimits the targeted vowel on
the spectrogram shows that there is a very sensitive gliding towards the end of
the word but it is not significant, and a movement towards a more central vocalic
position would have implied a raise of the first formant so that its higher