Škoda DuoBell: A bicycle bell that outsmarts even smart headphones - Škoda Storyboard

Pedestrians wearing headphones are exposed to an increased risk of accidents. In an effort to reduce collisions with cyclists, Škoda Auto, in collaboration with scientists, introduces an innovative bicycle bell whose sound can penetrate even active noise cancellation systems. In doing so, it helps prevent injuries to both pedestrians and cyclists.

Škoda Storyboard

I think it's time for some sort of a safety standard for a sound frequency to be reserved exclusively for alarm/alert use and that ANC systems have to let through.

It goes without saying, use of said frequency should be prohibited for other purposes, especially marketing.

However, deaf people are allowed to drive, cycle, walk etc. so sound won't always work anyway.