He was making inventories for something he called his inventory of echoes. And if you’re wondering what inventories of echoes are, this is what they are. Inventories of echoes are things made of sounds, sounds that got lost but were found by someone, or that would get lost unless they were trapped by someone, someone like Pa, who would make an inventory with them. So they were like a collection, or like a museum of sounds that did not exist anymore but that people would still be able to hear thanks to people like Papa who made them into inventories.
