Taking the re-imagined BSG Vipers as an example, I would think that during pressurized cockpit or inside-the-helmet shots, the audience would be able to hear the sounds of the cannons firing. The sound waves would be able to transfer through the wing, into the fuselage, into the human being attached to the fuselage, and then into the pressurized helmet/cockpit, where the atmosphere would be able to transmit the sound waves into the ear. Unless, I'm overestimating the distance that sound waves can travel through dense objects.
I honestly have no idea whether or not this would be true, but it makes sense.
Since the cockpit and/or helmet would be pressurized, sound would obviously travel *in* it; otherwise we wouldn't have been able to hear Mr. Armstrong. What I don't know is how an external sound would transmit *to* the pressurized area.
The recent reboot of BSG had both if memory serves... I recall some scenes showcasing total silence ala 2001/2010, and some with plenty of crashing, banging and so on and so forth.
I bet if we tracked down some quality NASA footage we could answer the question. If the physical structure of the craft is sufficient to communicate *direct* waves (as opposed to indirect; such as an event a few feet away, in vacuum, with no physical attachment to the shuttle) then we should be able to hear the nozzles firing when the shuttle maneuvers.