Well, we were in our school's reccess (sorry for bad english) and since he had a good concentration, he decided to do Nitrous, since time was short (15 minutes of reccess) When he finished, he started giggling a bit, was kind of dizzy and had little balance (I don't know if he faked it, cause he overdid it a little). After the class he told me in the first 30 minutes he heard a man singing (a Zakk Wylde with Kurt Cobain voice) some words that he wrote down while the voice sang, I don't know if he faked this one or if he has schizophrenia, because by what I know, Nitrous doesn't cause hallucinations (or does it?) and the lyrics were pretty intelligent for him, i'll try to bring the lyrics, that some parts don't make sense or he didn't understand correctly.
Hope you liked -my friend's- experience!
-Karapar