Been listening to Dan Carlin’s Hardcore History lately, specifically the WWI Blueprint for Armageddon section. In part 3 he describes what is known as drumfire. That is when the shelling was so intense that it literally sounded like a drumroll. Just think about that for a second and imagine enduring it hungry, wet, tired and cold and only 18 years old.
I’ve read that during some of the later fighting, the barrages were so intense that one couldn’t even distinguish between the explosions. It just sounded like one hours-long explosion.