[wodenokoto]

The point is that the sum of added and reduced noise is smaller in the noise cancellation than in non-noise cancellation, unless you are in an optimized environment.

[corv]

The problem is that voices or crying babies will be more audible in a noisy environment when using active noise cancelling headphones because they only effectively attenuate low frequencies.

[sjwright]

In a room with a crying baby, all pretense of an audiophile experience is gone, no matter what.