Speech, the ability to verbalize a thought or idea is considered the essence of being human. Ultimately all that we collectively think as humanity happens in our material creation and reality.
The expression of an idea or thought in action has its basis in sound whether as a subliminal thought process or expressed verbally through the spoken word. According to scientific research both subliminal thoughts and verbalized expressions carry the same impact and power at the subconscious level which is thought to comprise 99.9% of what underlies material manifestation. In other words, as you think so are you!