The award, instituted by Swarlaya cultural forum and Kairali TV, carries Rs 1 lakh, citation and memento.
The selection was made by a jury headed by former Kerala Culture Minister and CPI(M) leader M A Baby.
"Soundararajan has been a legendary presence in south Indian film music for six decades.
His songs have been enjoyed by Indian music lover cutting across regional and linguistic barriers," the jury noted.
Popularly known as "TMS", Soundararajan has rendered voice for Tamil mega stars of yesteryear like Sivaji Ganesan, M G Ramachandran and Gemini Ganesan.
Apart from Tamil, he has also sung scores of songs in Telugu, Kannada and Malayalam, giving voice to veteran actors like A Nagaeswara Rao, N T Rama Rao and Raj Kumar.
Known for his voice modulation skills, Soundararajan especially excelled in high-pitch songs, the jury noted.