A phoneme itself is a type with tokens, and so we'd also need an account of what a phoneme is, and what its tokens have in common (if anything). Saying what a phoneme is promises to be at least as hard as saying what a letter is. Phonology, the study of phonemes, is distinct from phonetics, the scientific study of speech production. Phonetics is concerned with the physical properties of sounds produced and is not language relative. Phonemes, on the other hand, are language relative: two phonetically distinct speech tokens may be classified as tokens of the same phoneme relative to one language, or as tokens of different phonemes relative to another language. Phonemes are theoretical entities, and abstract ones at that: they are sometimes said to be sets of features. The bottom line is that the phonological word is not the lexicographical one either.