Why don’t explosions hurt your ears more? To a layperson like myself, it would appear that the percussive power of a gunpowder explosion is a lot more than that of sound coming from a stereo speaker. And yet I see people in movies dusting themselves off and walking away after a car bomb goes off nearby. Is this credible? Wouldn’t their ears be harmed? For the sake of argument, why don't minor explosions from firecrackers break eardrums instantly?

Your eardrums are actually fairly resilient and survive explosions better than many more rigid structures. It probably helps that your ears are rather small apertures compared to a large aperture like a window.

One pound per square inch of blast overpressure is sufficient to knock people down and smash glass windows. Three pounds per square inch of overpressure will shatter cinder blocks. Five pounds per square inch of overpressure will snap wooden utility poles.

But five pounds per square inch is only the threshold for eardrum rupture. The blast pressure level where 50% of eardrums rupture is fifteen pounds per square inch, much more than enough to devastate a building.