Sony MDR-NC20 Noise Canceling Headphones with Foldable Headband (Discontinued by Manufacturer) Reduces exterior noise by more than 70 percent (10 dB) so you can hear music against a quieter background Closed-ear design for even strong isolation from outside sound 30 mm drivers deliver deep bass down to 16 Hz and provide outstanding dynamic range Folding headband and pivoting earpads simplify storage in a backpack, briefcase, or purse Extended battery life approximately 45 hours with a single AAA alkaline battery