The Role of Sound in Meditation by Swami Nirmalananda Giri explains why and how Hindus use verbal sound as a tool in meditation. Nirmalananda draws from sources such as the Upanishades, works by I.K. Taimni and modern business psychology from the West in this eight-page long guide.
From the text:
“Sound, is the direct means to return our awareness to the inmost level of our beingand put us into touch with consciousness itself. In fact, consciousness is innate in sound. At the same time, sound rules all the levels of our being and has the ability to infuse all those levels with the highest spiritual consciousness. Sound has the power to “spiritualize” every bit of us.”