why does unicorn sound like whale?

I actually just watched the director's cut with the commentary track yesterday. Ridley Scott said that he wanted the unicorns "voice" to have a musical, otherworldy sound befitting what were essentially god figures. He felt the whale song with some adjustment fit the bill.

I was just wondering that. "So if Ferris Buhler's girlfriend touches a unicorn it can speak to whales? Boy, the magic in this movie is complicated."

Why does the unicorn sound like a whale? Er perhaps becuase it's 1985?!?!?

It was a nice touch by Ridley, if i do say so myself. It’s an odd mix, yet wonderfully otherworldly and fascinating (which, of course, is what it was intended to be). I love it.