Various companies market their headphones as being able to cancel noise. That's misleading at best, a lie at worst.

I'm not an audio engineer, but I understand that 'noise-canceling' headphones have small microphones which detect incoming noise and emit sound waves canceling out the incoming ones. So, a small subset of noise is 'canceled'. But you'll still be able to hear most kinds of noise.

'Noise-reducing' is much closer to the truth.

My AirPods Pro, for instance, seem to be decent at reducing low-frequency sounds that aren't very loud. But high-frequency sounds remain almost unaltered. They're only slightly quieter.

For a set of headphones to be truly noise canceling, it would literally need to cancel all noise from the outside world. As someone who's sensitive to noise, I have long dreamt of a device that achieves this at the press of a button. Imagine the bliss, especially for sleeping. (You could wear a vibrating bracelet for alarms.) Even if AirPods could truly cancel all noise, they're not very comfortable to wear to sleep.

Something I'd like to see is a device you can put in your room which creates a sort of 'sound barrier' along the walls of that room. As a result, no sound should be able to enter or escape the room. Such a device would also enable you to watch TV on full blast at 2am without your neighbors hearing anything. It would be a convenient, non-wearable solution. The device should be small enough to take with you so it can create a 'bubble' of a sound barrier around you wherever you go.

Alternatively, I could imagine a kind of ear surgery that allows you to toggle your hearing on and off – maybe by implanting a small device near your ears that blocks and unblocks the nerves that process audio information to your brain. After all, if there is no incoming audio signal to your brain, it won't produce the quale of hearing anything. But this solution may not be as good as the device that creates a sound barrier around you because it cannot do anything about your skull vibrating, which also causes you to perceive noise. For example, I believe deep bass sounds enter not only through your ears but also through the vibrations of your skull. So there'd still be some incoming audio signal.

Looking further into the future, I suspect that, once we understand what qualia are, we will be able to manipulate and turn them off at will. And once we each move our consciousness from wetware (brains) to hardware (silicon-based computers), we will understand our underlying hardware fully. Canceling noise should be a piece of cake then.

Noise pollution is a serious and non-trivial problem. Health problems abound due to lack of sleep. 'Noise-canceling' headphones provide some relief and are better than ear plugs, but their producers have set the bar too low and consequently lie to customers.