Dhvani- The Indian theory of sound.
Poetry in which the uttered words and the meanings keep a lower profile than the indicated meaning, such poetry is called Dhvani. Sphota: The words and sounds that reach the ears are temporary and thereafter, cannot lead to meaning. Each word is a combination of several Varna and each word has a fine facsimile. Although the sound waves disappear, this facsimile remains leaving a unified imprint on the mind.
The fine and the permanent sound imprint is called Sphota in Indian grammar. The consonant Varna bby which the Sphota is uttered are called Dhvani. Thus it is that from the temporary Vaarnas the permanent Sphota words emerge. Similarly from the temporary words emerges permanent meanings.