On Formants : Cress Books : 9780999757420 : 0999757423 : 01 Jan 2020 : This book presents results in a study toward bringing acoustic and articulatory phonetics together for sonorant sounds, and, in particular, vowel production. Peter Ladefoged suggested proceeding in this project in his textbook, A Course in Phonetics. In acoustic phonetics the resonances, or formants, of the vocal the vocal tract is the primary way that vowels are characterized. In the present book, formants are examined using a physical acoustics approach; pressure, velocity distributions and energy densities of the formants of sonorants are used to examine tubes described by area functions. It is discovered that constriction length should be employed in an articulatory description of sonorants, in addition to the degree of constriction, place of constriction. Additional important parameters for English vowels are degree of lip rounding and larynx height. A new mathematical quantity called spatial phase is derived