Table 1. Summary of the mixed effects logistic regression models
| F1 | F2 |
| /ʌ/ref. vs. /ɨ/ | β (SE) | t-value | β (SE) | t-value |
| (Intercept) | 1.01 (0.11) | 8.82 | –0.77 (0.03) | –23.80 |
| Vowel/ɨ/ | –1.29 (0.08) | –14.8 | 0.52 (0.05) | 9.40 |
| Ageteen | –0.44 (0.16) | –2.78 | –0.23 (0.04) | –5.12 |
| Ageadult | –0.34 (0.20) | –1.73 | –0.13 (0.05) | –2.35 |
| Ageelderly | –1.14 (0.21) | –5.37 | 0.19 (0.07) | 2.70 |
| Vowel/ɨ/:Ageteen | 0.13 (0.12) | 1.11 | 0.17 (0.08) | 2.23 |
| Vowel/ɨ/:Ageadult | 0.16 (0.15) | 1.04 | 0.25 (0.10) | 2.58 |
| Vowel/ɨ/:Ageelderly | 0.85 (0.17) | 4.91 | –0.60 (0.10) | –5.87 |
| /o/ref. vs. /u/ | β (SE) | t-value | β (SE) | t-value |
| (Intercept) | –0.34 (0.07) | –5.21 | –1.08 (0.04) | –28.40 |
| Vowel/u/ | –0.07 (0.07) | –0.99 | 0.14 (0.05) | 3.17 |
| Ageteen | –0.33 (0.09) | –3.59 | –0.15 (0.05) | –3.05 |
| Ageadult | –0.23 (0.11) | –1.97 | –0.13 (0.06) | –2.19 |
| Ageelderly | 0.05 (0.13) | 0.35 | –0.13 (0.09) | –1.42 |
| Vowel/u/:Ageteen | 0.10 (0.09) | 1.03 | | |
| Vowel/u/:Ageadult | 0.35 (0.11) | 3.08 | | |
| Vowel/u/:Ageelderly | –0.67 (0.14) | –4.85 | | |
Statistically significant parameters (p<0.05) are in boldface, and marginally significant parameters (0.05≤p<0.1) are in italics.