Daniel Jones was a British phonetician who studied under Paul Passy, professor of phonetics at the École des Hautes Études at the Sorbonne. He was head of the department of phonetics at University College London.

Cardinal vowels are a set of reference vowels used by phoneticians in describing the sounds of languages. They are classified depending on the position of the tongue relative to the roof of the mouth, how far forward or back is the highest point of the tongue, and the position of the lips.