The sound doesn't have to be valuable to the animal: I could raise the animal in something that could be hypothetically valuable, like the sounds that simulate the sounds of a native language of a child.
这个声音不必对这个动物有价值。 我可以让这个动物生长在一个假设有价值的声音环境里， 比如把声音背景设置成模仿 一个小孩母语的声音。