Table 3. Average difference in values before and after the intervention for self-assessed and acoustic voice indicators of the teachers from a public school, according to the intervention groups. Salvador, BA, Northeastern Brazil, 2013.
| Indicator | Vocal warm-up (n = 14) |
Breathing training (n = 17) |
|
||
|---|---|---|---|---|---|
| Before |
After |
p* | |||
| Average difference | SD | Average difference | SD | ||
| VHI (%) | -8.75 | 10.13 | -6.61 | 6.84 | 0.76 |
| F0 (Hz) | -9.96 | 17.14 | -6.15 | 26.11 | 0.30 |
| Jitter (%) | -0.02 | 0.10 | 0.25 | 0.89 | 0.20 |
| Shimmer (%) | 0.20 | 0.89 | 1.41 | 2.30 | 0.77 |
| Noise (dB) | -0.01 | 0.14 | -0.004 | 0.67 | 0.49 |
| GNE ratio (dB) | 0.02 | 0.13 | 0.001 | 0.67 | 0.74 |
* Mann-Whitney U test.