Aparently they understand our language but can't speak it thats the 6th sense she's talking about.I don't think she's a hippie, haven't seen one in my life in Romania.
But then again how would we know they understand what we say ? Thats like training a dog to shake hands.
I question your teacher's sanity. If dolphins are smarter than humans because they have been learned what a few words mean, then gorillas could also be smarter than humans as some of them have been taught sign language. Then there's parrots that have learnt what words mean and how to say them. Hell, parrots have even taught each other human languages. And then there's all the animals that you can train to respond to commands.
Then again, how many people on this forum alone can speak 2+ languages? I think that would beat the dolphins learning another one.
Unless, of course, she means the dolphins didn't learn the language and that they just know it but I somehow doubt anyone is out of touch with reality enough to think that dolphins can understand every single word of every single language known to man. And if so, why just human languages?
Perhaps your teacher just loves dolphins.