My village has seen several raids. Prior to 1.16 the raid horn (ominous horn blares; event.raid.horn) was slightly louder than the background noise.
I updated to 1.16 and triggered a raid, and the horn is now louder by about 10dB. You scared my cat!
With my TV volume turned down to 1 so I can't hear any other sound effects, the raid horn is still on the loud side of comfortable.
This is measuring from the bell in the centre of the village. It's an artificial village, if that makes a difference.