SOVT or semi-occluded-vocal-tract means simply that the mouth is kept partially closed during vocalizing. This is the case when you hum, do the lip roll, slide with /ng/ or sing a melody with a rolling /r/, for instance. In addition, many voice teachers utilize phonating through a straw or a rubber pipe, which are effective ways to get the benefits that SOVT exercises provide.
Please note: luckily today it is possible to use nature-friendly straws that are decomposable, in stead of plastic straws.
True Vocal Fold Vibration Easier With Less Effort
SOVT exercises provide multiple benefits. The advantage is provided by the back pressure that is reflected back downwards from the vocal tract towards the true vocal folds while the pressure from the lungs is working its way upwards at the same time. This phenomenon enables free vibration of the true vocal folds with less effort.
Reduces Breathiness
The created back pressure helps the edges of the vocal folds to get closer to each other during vibration, which reduces breathiness.
Helps To Get Rid Of Breaks
Difficulties with passaggio, or the bridge between registers? SOVT exercises may help you in changing smoothly from a vocal fold vibratory pattern to another due to the balancing effect of the back pressure.
Helps To Lose Vocal Strain
SOVT exercises open up the supraglottic (above the true vocal folds) space which provides better conditions for free vocal fold vibration. In addition, phonating without extraneous tensions is more likely.
Prevents Vocal Problems?
Singing through a straw is an effective way to teach your instrument to find a good balance between the vocal fold vibration and the air pressure, which can help reduce tendency to push. At the same time the benefits mentioned above are also being reinforced.
Great Way To Warm-Up And Cool-Down
SOVT exercises are great for vocal warm-ups. It is also an excellent way to cool off your instrument after a day of heavy vocalizing, for example. Different straws and tubes are being used in voice therapy, as well.
If you wish to learn more about SOVT exercises, there is plenty of information available online. We recommend reading an article on the topic at Voice Science Works.