Its starting about 0:37 where the sound becomes brazen and crisp and changes to a higher tune.
Also a good example of that Ringmodulator sound can be heard at the end sequence in "Jon & Vangelis - I`ll find my way home" :
http://www.y**tube.com/watch?feature=player_detailpage&v=2oANV6SQhwI#t=260
copy and paste and replace ** with ou ;-) !! I do not want to have the YT video included because the time stamp gets lost