List of Illustrations, Preface, CHAP. I. INTRODUCTION, CHAP. II. PRELIMINARY OBSERVATIONS AS TO THE VOCAL ORGANS, AND THEIR FUNCTION IN SPEECH. CHAP. III. OBSERVATIONS ON THE VOWEL RESONANCES, CHAP. IV. EXPERIMENTS WITH MODELS (VOWELS), CHAP. V. VOWEL SOUNDS—CONCLUDED—SINGLE OR DOUBLE RESONANCE ?, CHAP. VI. OBSERVATIONS AND EXPERIMENTS ON THE CONSONANTS, CHAP. VII. THE ORIGIN AND DEVELOPMENT OF SPEECH, CHAP. VIII. VOWEL AND CONSONANT SYMBOLISM, CHAP. IX. THE DEVELOPMENT OF DIFFERENT LANGUAGES, CHAP. X. VOICE PRODUCTION, CHAP. XI. MOUTH RESONANCE IN RELATION TO LARYNGEAL PITCH, CHAP. XII. ARTIFICIAL SPEECH AND SONG, CHAP. XIII. THE ADVANCEMENT OF LANGUAGE AND ITS NOTATION, APPENDIX. I. A NOTE ON THE DOUBLE-RESONATOR THEORY OF VOWEL SOUNDS, APPENDIX. II. TABLE OF FREQUENCIES i.e NUMBER OF COMPLETE VIBRATIONS PER SOUND, CORRESPONDING TO THE EQUAL TEMPERAMENT SCALE, APPENDIX. III. AUDIOGRAM OF THE AUTHOR'S HEARING, APPENDIX. IV. PAGET AND CLAY VARIABLE VOWEL MODEL, APPENDIX. V. SOME EXPRIMENTS WITH TUBULAR VOWEL MODELS, APPENDIX. VI. CONSONANT RESONANCES, APPENDIX. VII. AMERICAN AND ENGLISH VOWELS, APPENDIX. VIII. POLYNESIAN LANGUAGE, Index