 In trying to figure out how the emerging doctrine of nityatva (“permanence”, “immutability”) of language causes problems with the notion of transformation (vikāra) and how these problems are eventually answered by developing new concepts, we should note two issues, i.e., temporal fixity or flexibility of individual sounds, and the compatibility of the notion of sequence of sounds, or utterance as a process stretched in time. From within the new paradigm of nityatva or eternality of sounds, Kātyāyana concludes that the true sounds (varṇa) are fixed in their nature in spite of the difference of speed of delivery (Vārttika 5 on P. 1.1.70, Mahābhāṣya, I, p. 181). The speed of delivery (vṛtti) results from the slow or fast utterance of a speaker (vacana), though the true sounds are permanently fixed in their nature. Here, Kātyāyana broaches a doctrine that is later developed further by Patañjali, and more fully by Bhartṛhari. It argues for a dual ontology. There are the fixed true sounds (varṇa), and then there are the uttered sounds (vacana, “utterance”). It is Patañjali who uses, for the first time as far as we know, the term sphoṭa to refer to Kātyāyana’s “true sounds which are fixed” (avasthitā varṇāḥ) and the term dhvani (“uttered sounds”). Patañjali adds an important comment to Kātyāyana’s discussion. He says that the real sound (śabda) is thus the sphoṭa (“the sound as it initially breaks out into the open”), and the quality [length or speed] of the sound is part of dhvani (“sound as it continues”) (Mahābhāṣya, I, p. 181). The term sphoṭa refers to something like exploding or coming into being in a bang. Thus it refers to the initial production or perception of sound. On the other hand, the stretching of that sound seems to refer to the dimension of continuation. Patañjali means to say that it is the same sound, but it may remain audible for different durations.