Voice — Audiobooks
Expressive Voice Culture, Including the Emerson System
by Jessie Eldridge Southwick

The Mechanism of the Human Voice
by Emil Behnke
Vocal Expression: A Class-book of Voice Training and Interpretation
by Katherine Jewell Everts

The Voice and Spiritual Education
by Hiram Corson

The Brain and the Voice in Speech and Song
by F. W. (Frederick Walker) Mott

Psycho Vox; or, The Emerson System of Voice Culture
by Charles Wesley Emerson

Duality of Voice
by Emil Sutro