Guess I was wrong about space. Thank you for teaching me this about space. Wow, i didn't know that there was sound in space! Hope I can find out more.

This is a major misconception about space. There IS sound in space since normal interstellar space isn’t a total vacuum. It’s below the level of human hearing but artificial sensors can detect it and if a sound is traveling through space and encounters an area of higher particle density (IE a ship's atmosphere) it possible (but very unlikely) that the sound could heard assuming the sound was extremely loud.

Additionally the sound could be amplified though the ships speakers for the benefit of the crew- namely the pilot.

I'm hoping they're just in the trailer as attention-grabbers for all the people who have'nt seen the show.