Backest Definition

Martin J. Ball and Nicole Müller (2005), Phonetics for communication disorders, p. 56:He set up two anchor points for his system using articulatory criteria: cardinal vowel 1 was the highest, frontest vowel that one could make without the sound becoming a consonant, and cardinal vowel 5 was the lowest, backest vowel one could produce without pulling the tongue back into the pharynx.