08:45 Jul 22, 2010 

I'll take an educated guess at this. BTW I work with sound mix /design for film, so I'm not just winging it -°)

Again "son itératifs" is from the electro-acoustic vocabulary. I think here it refers to micro sounds which repeat over and over to give the impression of a sonic mass.

Grains = as in granular synthesis, also the grain of the sound being a textural quality. Term often used in computer music.

Tenues to mean sustain in the musical sense. But I think it means the grain is smoothed out by the sustain.