Explanation

Because sound is just vibrating air, space has no air to vibrate and therefore no sound in a vacuum.

Sound waves below 20 Hz are known as infrasound.

Sound waves above 20 kHz are known as ultrasound

Sound waves transmit a medium such as a gas, liquid, or solid.

• The speed of sound in air is about 343 meters per second
• The sound travels at 1,481 m/s in water 
• The speed of sound in a vacuum is zero meters per second.