"How wonderful is the human voice! It is indeed the organ of the soul! The intellect of man sits enthroned visibly on his forehead and in his eye; and the heart of man is written on his countenance. But the soul reveals itself in the voice only, as God revealed himself to the prophet of old, in "the still, small voice," and in a voice from the burning bush. The soul of man is audible, not visible. A sound alone betrays the flowing of the eternal fountain, invisible to man!
Longfellow - photo from Internet