I have no whistling. EASY TO USE. I suggest that anyone looking at these you only use them for things 5 lbs or less. I recently purchased and have been using this Sigtuna 16mm Bike Lock + Cable Combo and could not be happier. When battery gets low it emits a loud chirp that you do NOT want to hear wearing the headband. I mentioned in my last update that I’d be keeping my E7’s as a set of backups and, well, it has come to be. Quality of build and sound and mic is quite good. Nella parte davanti dove cè la luce la gomma è più sottile e cè anche il copri foro della carica. Just go for it. For the price it’s okIt swivels East but pops out of holder if pushed too fast or pulling something of due to lack of security to lock in.