A Study on Vocal Attack During Voice Therapy Exercises Using Photoglottography

Objective

There are various exercises for voice therapy, but current evidence is insufficient to decide the most effective training technique for each type of dysphonia. This study focused on vocal attack as one of the causes of dysphonia. Hence, vocal attack during voice therapy exercises was investigated using photoglottogram (PGG).

Methods

Eighteen healthy adult subjects (10 males and 8 females) were included in this study. The first to fifth vocal waves during natural voice, hard and soft voice onset, and semi-occluded vocal tract exercises (SOVTE: humming, tubing, and lip trill) were assessed. We also calculated the 25% vocal fold open quotient (OQ) using a PGG and compared these parameters.

Results

The 25% OQ did not show any sex-related differences. In the first wave, the 25% OQ for hard attack was significantly lower than that for soft attack, tongue-out humming, and lip trill. In contrast, the 25% OQ value for soft attack was significantly higher than that for humming, 6 mm tube phonation, and lip trill. The 25% OQ values differed between SOVTE procedures; it was higher for the 13 mm tube phonation than for the 6 mm tube phonation. The 25% OQ at voice onset in the first to fifth waves differed depending on the SOVTE technique, indicating different voice onset patterns.

Conclusions

These results suggest that appropriate selection of SOVTE tailored for each patient may have benefit in further voice improvement. Future research should focus on conducting a similar study on patients with dysphonia.