(स्फोट, ˈsphoːʈɐ; "bursting, opening", "spurt") is an important concept in the Indian grammatical tradition of Vyakarana, relating to the problem of speech production, how the mind orders linguistic units into coherent discourse and meaning.
The theory of is associated with Bhartṛhari ( 5th century), an early figure in Indic linguistic theory, mentioned in the 670s by Chinese traveller Yijing. Bhartṛhari is the author of the Vākyapadīya ("[treatise] on words and sentences"). The work is divided into three books, the Brahma-kāṇḍa, (or Āgama-samuccaya "aggregation of traditions"), the Vākya-kāṇḍa, and the Pada-kāṇḍa (or Prakīrṇaka "miscellaneous").
He theorized the act of speech as being made up of three stages:
Conceptualization by the speaker (Paśyantī "idea")
Performance of speaking (Madhyamā "medium")
Comprehension by the interpreter (Vaikharī "complete utterance").
is of the "speech monistic" school which identifies language and cognition.
According to George Cardona, "Vākyapadīya is considered to be the major Indian work of its time on grammar, semantics and philosophy."
While the theory proper () originates with , the term has a longer history of use in the technical vocabulary of Sanskrit grammarians, and Bhartṛhari may have been building on the ideas of his predecessors, whose works are partly lost.
Sanskrit is etymologically derived from the root 'to burst'.
It is used in its technical linguistic sense by Patañjali (2nd century BCE), in reference to the "bursting forth" of meaning or idea on the mind as language is uttered. Patañjali's sphoṭa is the invariant quality of speech. The acoustic element (dhvani) can be long or short, loud or soft, but the sphoṭa remains unaffected by individual speaker differences. Thus, a single phoneme (varṇa) such as /k/, /p/ or /a/ is an abstraction, distinct from variants produced in actual enunciation.
Eternal qualities in language are already postulated by Yāska, in his Nirukta (1.1), where reference is made to another ancient grammarian, , about whose work nothing is known, but who has been suggested as the original source of the concept.