Yep, I know what a splitter is, though the splitters to which I am best accustomed are the sort used in electronic equipment, such as connecting two video game systems to the same port. Like, "I can connect both my Xbox and my NES to the TV!" So, given that, I was a bit baffled about why you'd carry such an item around with you.

But for headphones...that makes sense for an ethnomusicologist. :)