VOICE (OF. vole, voiz, vuiz, Fr. moix, from Let. vox, voice; connected with Gk. 'giros, epos, word, Skt. cams, speech). The audible sound produced in the larynx of any animal possessing that organ. The primary vocal elements originating in the larynx are modified in their passage outward through the pharynx and month so as to form articulate speech o• musical sounds, i.e. speaking and singing. The whole respiratory apparatus is concerned in the pro duction and modulation of the voice. The lungs force a column of air, under varying, degrees of pressure, through the trachea o• windpipe against the vibrating portions of the larynx (q.v.), generating a sound which is modified by the tongue, teeth, lips, etc. The study of the varying conditions in the interior of the larynx is made possible by the use of the laryngoscope (q.v.). On attempting phonation, the arytenoids (mov able cartilages to which are attached the pos terior ends of the cords) are seen to raise them selves in the fold of mucous membrane which covers them, and rapidly approach each other. This movement approximates the edges of the vocal cords, and consequently narrows the open ing of the glottis. During the emission of the most acute sounds the glottis contracts into a mere line. The arytenoid cartilages are raised and meet in the median line, the epiglottis is drawn outward, and a short, stiff tube is then formed above the glottis, all these parts being in a state of extreme tension. It is impossible to study with the laryngoscope the manner of for mation of the gravest chest tones, because the arytcnoid cartilages approach each other closely and bend under the border of the epiglottis, which is depressed, so that. the cords are hidden. The larynx possesses within itself more delicate powers of adjustment than any musical instru ment. In addition to the movements already mentioned, the vibrating portions of the cords can be shortened or lengthened. or limited to their edges: the free edges can he sharpened or blunted, and the whole cord can lie flattened out like a ribbon. The entire mechanism is adapted
to meet varying degrees of pressure of the column of air in the trachea, and the quality of the sound produced is further modified by the adjustable centres o• ventricles of the larynx.
Tone has three attributes: strength or loud ness, pitch, am] quality or timbre. Strength de pends upon the energy of the expirating blast, and upon the structure and adjustnwnt of the vocal organ and the resonance apparatus. Pilch depends upon the rapidity of the vibrations, this being determined by the length and tension of the cords. Quality, as has been shown in the article AcousTfcs (q.v.), depends upon the char acter and number of the partial tones t overtones) accompanying any fundamental note sounded; and this is determined mainly by the form and thickness of the cords.
The principal difference between male and female voices lies in their pitch; but they are also distinguished by their quality, the female voice being softer. There are two kinds of male voice. bass and tenor, and two kinds of female voice, contralto and soprano, all differing from each other in quality. The essential difference between bass and tenor and contralto and so prano is not range merely, for the bass and con tralto often sing very high notes, but is one of tone or timbre. which distinguishes them even when they are singing the same note. The bary tone and mezzo-soprano are the intermediate voices of the male and female, respectively. The boy's larynx is like that of the female. and his voice is similar in range and pitch, hut is some what louder and different in timbre. At puberty the boy's larynx undergoes a rapid change, into the bass or tenor, and is said to crack or break, the peculiarity then noticed being due to imper fect control of the muscular mechanism, and also to the congested and swollen state of the mucous membrane of the cords, incident to active growth. See SINGING.