In this chapter we will be describing and classifying speech sounds phonetically (in the next chapter we return to the phonological definitions). We shall find that consonants can be voiced or voiceless and are most easily described wholly in articulatory terms, since we can generally feel the contacts and movements involved. Vowels, on the other hand, are voiced and, depending as they do on subtle adjustments of the body of the tongue, are more easily described in terms of auditory relationships.