Table 4.
Formant frequencies, acoustic vowel space, formant centralization ratio, and vowel duration at OFF- and ON-stimulation: means (standard deviations), F and P values.
| /i/ | /u/ | /a/ | Acoustic vowel space (Hz2) | Formant centralization ratio | Vowel duration (ms) | ||||
|---|---|---|---|---|---|---|---|---|---|
| F1 (Hz) | F2 (Hz) | F1 (Hz) | F2 (Hz) | F1 (Hz) | F2 (Hz) | ||||
| OFF-stimulation | 311.5 | 2233.1 | 329.2 | 1186.6 | 583.3 | 1736.3 | 152036 | 1.240 | 130.2 |
| (54.4) | (219.0) | (66.6) | (283.1) | (127.6) | (263.5) | (14251) | (0.035) | (8.8) | |
| ON-stimulation | 307.6 | 2345.7 | 328.5 | 1077.0 | 680.1 | 1753.0 | 227759 | 1.142 | 138.4 |
| (45.1) | (264.4) | (61.3) | (250.1) | (91.1) | (268.0) | (17905) | (0.031) | (10.5) | |
|
| |||||||||
| Change | +75723 | −0.098 | +8.2 | ||||||
| (11504) | (0.20) | (5.1) | |||||||
| F | 43.327 | 24.482 | 2.665 | ||||||
| P | <0.000∗ | <0.01∗ | >0.05 | ||||||
∗Significant effect.