Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. The study of the physiology of the voice has been greatly facilitated by the use of the laryngoscope. This instrument, by laying bare the interior of the larynx, shows how the glottis proceeds to produce sounds and registers. It shows, also, the manner in which the ringing and veiled qualities are communicated to the voice. These qualities - produced by the glottis-are distinct from the characteristics of the voice called timbres, and are originated in the pharynx by quite another mechanism. All this should dispel many false' ideas afloat on the question of voice production.
