I couldn't find how to make a sound like the one that starts at 0:58 :Is there a plugin that enables how to do it or do you modify an instrument to do it? Thanks!
That's just a sampled 'aaah'(vocal), played in different keys. Just find a bit of vocals you like, drop it in a sampler, pitch it up by an octave or more and you;re ready. It may help to loop a few ms so that it stays more constant in pitch, timbre and amplitude. The amplitude envelope sounds like a sharp attack, no decay, full sustain and the tiniest bit of release.