[Evan Thomas]

You're right, DNS, and it's actually even worse than that.

It's no different from a ricochet. A bullet that bounces off a hard surface can still have enough kinetic energy to injure you, and reflected sound can have enough acoustic energy to damage your ears.

If you're firing a handgun with a muzzle blast that measures 165 dB in a small room with reflective walls, ceiling, and floor, that's going to produce six reflected impulses within a few milliseconds of the direct sound; if the reflected impulses each measure around 150 dB, which is entirely possible, your ears have now been exposed to seven potentially damaging acoustic events instead of just one, and to the extent that the impulses overlap when they reach your ears, they'll act like a single, more intense acoustic event, and the SPL will be the sum of their acoustic energy, and will have even more potential for causing hearing damage.

The damaging effect of noise is cumulative: exposure to several intense acoustic events is more harmful than exposure to just one, and a longer event will do more damage than a short one of the same intensity. It makes no difference to your ears if these events are direct, from the original sound source, or reflected.