Editing Dragon Dictate (section)

==== Three-level Phonology ====
This three-level approach alIows Dragon Dictate to adapt quickly to the user’s own speech, approaching the reference speaker’s performance within a few thousand words.

* Phonemes: It comprises 24 consonants, three unstressable syllabic resonants, and 17 vowels, including diphthongs and syllabic /r/.

* Phonemes in context (PICs): the fundamental unit of Dragon phonology, a PIC represents an augmented triphone, comprising:
** the phoneme before the one being modeled, as context
** the phoneme being modeled
** the phoneme after the one being modeled, as context
** the degree of prepausal lengthening of each phoneme due to its position in the word.

* Phonetics elements(PELs): Most instances of English /s/ have a lot in common acoustically, and even a highly context-dependent consonant like /t/ can show significant constancy. We implement this similarity as a slice of a very coarse spectrogram, a steady state called a phonetic element, or PEL.