Semi-Occluded Vocal Tract Exercises (SOVTE) are a set of techniques that are based on a common principle, which is the increase of the vocal impedance through the semi-occlusion of the mouth. These exercises are mainly used by speakers and singers, but their use is increasing also in voice therapy. A new device has been developed (Vocal Feel) that combines the benefits of SOVTE with the vocal fold hydration. It is made up of a facemask, a humidifier-filter with a unidirectional valve and a bubble equipment. Preliminary tests, which use both static and variable impedance techniques, have shown promising results in the increasing of voice resonance and proprioception of singers. An experimental campaign has started to objectively assess the effects of such an equipment on the vocal performance that is based on the estimation of parameters of the recorded vocal signal of singers, who are equipped with a contact microphone and a microphone in air. The former allows the signal related to the vocal-folds vibration to be sensed, while the latter is used to acquire the signal at the output of the mouth. Example of estimated parameters are sound pressure level, fundamental frequency, Cepstral Peak Prominence Smoothed and singing power ratio.