From the human Gospel by Sri Ganesan and John Troy: Daivarata, a disciple of Sri Ramana Maharshi is the only person who has recorded an evaluation of Bhagavan‘s voice.
quote: "Maharshi‘s voice is melodious and soft as that of a child; it is exceedingly sweet. At times it is so soft that it is not even heard clearly. It must be heard with attention. When we hear his voice, we feel as if we are hearing a Divine and subtle voice coming across the firmament. His is the form of Divine speech so vastly extolled in the Vedas."