| Variable |
Before treatment (%) |
After treatment (%) |
| Overall correct answer |
22.4 |
26.4 |
| Bilabial |
23.8 |
21.5 |
| Dental-alveolar |
15.6 |
31.9 |
| Palato-alveolar |
10 |
8.8 |
| Palatal |
37.1 |
31.4 |
| Velar |
3.8 |
15 |
| Glottal |
100 |
80 |
| Vowels |
84 |
76 |