Both those are examples of vibrations directly imparted into the metal of the machine by a force in direct contact with the metal.But, like on present day Mars, with only 5 percent atmosphere you can hear sound given off by various things. The various Mars rovers have had microphones to record the sound of wind and even pick up the fainter sounds of the rovers motors.
So yes, common sense would dictate that thin atmospheres would definitely be conducive to sound.
The pressure will affect the echo it hears from a loud noise reverberating off further away objects, or just a far off noise in general.