You are attempting to mix fictional fantasy stories with real natural science. Levitation of tiny objects is possible for some light-weight objects if they are trapped in an "acoustic standing wave node" (you may Google that phrase). This mechanism does not apply the sort of thrust you are asking about where a human’s voice would generate enough thrust for a man to fly.
Experiment with a powerful acoustic emitter (speaker, for example). Using a sound source and a powerful audio amplifier, energize the speaker. Then hold a flat plate near the speaker’s output. Try to measure the force exerted on that plate. Reverse the measurement: try to measure the recoil force the speaker causes while emitting high power sound. Results in both cases: NONE. Therefore, no human, no matter how loud his voice may be, could propel himself to fly.