This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol1", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
Aphonia. When not dependent on organic lesion, or symptomatic of some other disease, this will sometimes yield to local faradisation applied to the muscles from without, and the skin also, or by operating through the pharynx. (See page 519.) The lee the strength and character of the voice, often incurred by those who speak much in public, may be relieved by the same measure. Other modes of applying the remedy, as by successive discharges through tin-organ from a powerful battery, by a galvanic current introduced by means of acupuncture, and by the simple apparatus of a small zinc and silver plate (see page 504), one on one side, the other on the other of the larynx, have also proved successful. But in these cases electricity, like all other measures, not unfrequently fails without any assignable cause.