What drives a physician, a speech therapist, and a singing teacher to collaborate on a book dedicated to semi-occluded vocal tract exercises?

There has long been significant interest from both the scientific and artistic communities in the topic of what are known internationally as Semi Occluded Vocal Tract Exercises (SOVTEs).

Such exercises are recognized worldwide for facilitating the attainment of an intuitive and rapid balance of the forces involved in phonation, and have proved part...