Acharya Prashant explains that the ability to speak does not prove the existence of a conscious entity within the body. He compares human speech to the sounds produced by inanimate objects like microphones, radios, and mobile phones, which function through mechanical processes. Just as a microphone amplifies sound or a radio transmits it without being conscious, the human body uses vocal cords and air vibrations to produce speech. He emphasizes that speech is often a mere reaction to external stimuli or a result of unconscious states, such as snoring or sleepwalking, proving that awareness is not a prerequisite for making sound. He further describes the entire process of hearing and speaking as purely mechanical and physical. Sound is essentially vibration, which is present throughout the universe, from the rustling of wind to waves in outer space. Spiritual progress, according to him, is the realization that the body and its functions are inert and mechanical. He references the Buddhist concept of Emptiness and the Vedantic concept of Witnessing to explain that there is no someone inside the body directing these actions. He concludes that the belief in a self inside the body, simply because it speaks, is a misunderstanding similar to thinking a ghost lives inside a radio.