Numerous NIH/PubMed studies indicate the nervous system regulating power of singing, mantra and vocal toning.

Effect of rosary prayer and yoga mantras on autonomic cardiovascular rhythms: comparative study

To test whether rhythmic formulas such as the rosary and yoga mantras can synchronise and reinforce inherent cardiovascular rhythms and modify baroreflex sensitivity.

Cardiorespiratory optimization during improvised singing and toning

We evaluated the effect of different forms of singing on cardiorespiratory physiology, and we aimed at disentangling the role of breathing from that of vocal production.

Exploring the Experience and Effects of Vocal Toning

Toning is a form of vocalizing that utilizes the natural voice to express sounds ranging from cries, grunts, and groans to open vowel sounds and humming on the full exhalation of the breath.