What is the speed of sound in a vacuum?

Since a vacuum is empty space, there is no medium for the sound to travel through. The speed of sound in air mainly depends on the temperature of the air. On average, it is about 343 meters per second (1,125 feet per second),

The speed of sound in vacuum is zero meters per second. Without a physical medium, sound can't propagate, so it can never get from here to there, no matter how short the distance is.