This structure is one half of what is known as The Wolf's Ears, located on the NCSU campus. Read below what the NCSU website has to say about it.
"Located on the grassy knoll in front of the library, the Wolf Ears have been a source of acoustic fun for years. With the Wolf Ears you can have a conversation with a friend that is sitting 40 feet away. Sit in one of them and have your friend sit in the other one and a whisper will be all you need to hear each other. No secrets, though, someone standing in between them might hear it too!" (http://students.ncsu.edu/top54/list.php?id=11)