THE BRAIN AND THE VOICE IN SPEECH AND SONG BY F.W. MOTT, F.R.S., M.D., F.R.C.P. 1910 PREFACE The contents of this little book formed the subject of three lectures delivered at the Royal Institution "On the Mechanism of the Human Voice" and three London University lectures at King's College on "The Brain in relation to Speech and Song." I have endeavoured to place this subject before my readers in as simple language as scientific accuracy and requirements permit. Where I have been obliged to use technical anatomical and physiological terms I have either explained their meaning in the text, aided by diagrams and figures, or I have given in brackets the English equivalents of the terms used. I trust my attempt to give a sketch of the mechanism of the human voice, and how it is produced in speech and song, may prove of interest to the general public, and I even hope that teachers of voice production may find some of the pages dealing with the brain mechanism not unworthy of their attention. F.W. MOTT LONDON _July, 1910_ CONTENTS THEORIES ON THE ORIGIN OF SPEECH THE VOCAL INSTRUMENT: THREE QUALITIES OF MUSICAL SOUNDS, LOUDNESS, PITCH AND TIMBRE THE VOCAL INSTRUMENT AND ITS THREE PARTS (1) THE BELLOWS AND ITS STRUCTURE: VOLUNTARY CONTROL OF BREATH (2) THE REED CONTAINED IN THE VOICE-BOX OR LARYNX: ITS STRUCTURE AND ACTION (3) THE RESONATOR AND ARTICULATOR, ITS STRUCTURE AND ACTION IN SONG AND SPEECH PATHOLOGICAL DEGENERATIVE CHANGES PRODUCING SPEECH DEFECTS AND WHAT THEY TEACH THE CEREBRAL MECHANISM OF SPEECH AND SONG SPEECH AND RIGHT-HANDEDNESS LOCALISATION OF SPEECH CENTRES IN THE BRAIN THE PRIMARY SITE OF REVIVAL OF WORDS IN SILENT THOUGHT CASE OF DEAFNESS ARISING FROM DESTRUCTION OF THE AUDITORY CENTRES IN THE BRAIN CAUSING LOSS OF SPEECH THE PRIMARY REVIVAL OF SOME SENSATIONS IN THE BRAIN PSYCHIC MECHANISM OF THE VOICE ILLUSTRATIONS FIG. 1. The thoracic cage and its contents 2. The diaphragm and its attachments 3. Diagram illustrating changes of the chest and abdomen in breathing 4. Diagram of the cartilages of the voice-box or larynx with vocal cords 5. Front view of the larynx with muscles 6. Back view of the larynx with muscles 7. Diagram to illustrate movements of cartilages in breathing and phonation 8. Section through larynx and windpipe, showing muscles and vocal cords 9. The laryngoscope and its use 10. The glottis in breathing, whispering, and vocalisation 11. The vocal cords in singing, after French 12. Vertical section through the head and neck to show the larynx and resonator 13. Diagram (after Aikin) of the resonator in the production of the vowel sounds 14. König's flame manometer 15. Diagram of a neurone 16. Left hemisphere, showing cerebral localisation 17. Diagram to illustrate cerebral mechanism of speech, after Bastian 18. The course of innervation currents in phonation THE BRAIN AND THE VOICE IN SPEECH AND SONG