Wikipedia
Anandavardhana (820–890) was the author of Dhvanyaloka, a work articulating the philosophy of "aesthetic suggestion". The philosopher Abhinavagupta wrote an important commentary on it.
Anandavardhana is credited with creating the dhvani theory. He wrote of dhvani (meaning sound, or resonance) in regard to the "soul of poetry." "When the poet writes," said Anandavardhana, "he creates a resonant field of emotions." To understand the poetry, the reader or hearer must be on the same " wavelength." The method requires sensitivity on the parts of the writer and the reader. The complete Dhvanyaloka together with Abhinavagupta's commentary on it has been translated into English by the eminent sanskritist Daniel H.H. Ingalls and his collaborators.