Low frequency is where it's most effective but I've just tested my AirPods without music playing vs my Sonos playing something with bass and it basically cleaned it up and almost made it a little more pronounced.
Definitely quieter but the bass specifically was almost more noticeable. YMMV.
Does there exist anywhere a comparison of how well different noise cancelling headphones work in terms of pitch of sound?
I am interested in something that can cut out some of the low pitched bass sounds from a neighbour's music.
I'm not familiar with whether this is something they're generally good at, or generally mediocre at.
Edit: as @aggi says above I understand that noise cancelling in generally good for continuous sounds rather than intermittent.