The field of speech science is often divided into the specialties of speech production and speech perception. Speech production is concerned with the way in which our thought and language are converted into speech. A number of theories seek to explain exactly how such amazing behavior is accomplished. Most theories share the view that there is a pre-articulatory (or planning) stage and a motor realization (or vocal tract control) stage, and that these stages are accessed in a precisely timed, hierarchical manner during speaking.

Speech perception researchers puzzle out how listeners can decode meaningful units of speech (phonemes) from a rapidly changing and highly encoded speech signal—a communication ability that is miles beyond the reach of most computers.