These headphones do two things: 1) block external noise passively and 2 actively cancel the sound pressure of external noise by producing an out-of-phase pressure wave. This means that your eardrum doesn't experience the pressure from the external noise, so you should be better protected.
My guess is that even the passive noise reduction of using closed earbuds helps considerably. When I'm in the NYC subway with $8 headphones I don't experience the painfully loud sounds from squealing trains/etc. 15-20 Db of reduction goes a long way towards protecting your hearing.
My guess is that even the passive noise reduction of using closed earbuds helps considerably. When I'm in the NYC subway with $8 headphones I don't experience the painfully loud sounds from squealing trains/etc. 15-20 Db of reduction goes a long way towards protecting your hearing.