Boost leak??

[(B1) MR_fanny]

hey guys, i have been noticing a strange sound from my turbo lately. when on boost up to 5k the turbo sounds fine(solid high pitch compression sound) but when it hits full boost after 5k it starts to hollow out slightly flutters. there is no noticable loss of performance...then again i only give it a proper fang it once in a full moon so i might have forgotten what it originally feels like. anyways the only 2 reasons that i can think of why its doin this is ,

1- the compressor fan in the turbo is loose and is about to shiit itself. thus makin the fluttery noise

2- i have a boost leak somewhere

any ideas guys?? oh yeah im only running stock boost so 5-7psi

cheers

[(B1) MR_fanny]

anyone?