If I understand correctly, noise cancelling headphones isolate a certain frequency or perhaps a sample of a frequency along an given timeframe. If this is true, then the isolated frequency can be amplified as well as dupilcated. I also assume that these devices have to have some sort of microphones for audio input. Headphones take the frequencies that they would normally cancel and amplify them so you could hear your friend ask you a question at twice the normal volume so you would end up answering them in a more reduced volume. You could also tune into other conversations when others think you are oblivious. A button would be included to revert their operation to noise cancelling cancelling cancelling headphones with twice the cancelling power.-- ricchris, Dec 31 2008 Prior Art on the HB (with a small difference). You haven't really described how these devices will work. Welcome to the Halfbakery. Please read the 'Help' section under 'Meta' data to your left.-- gnomethang, Dec 31 2008 There are headphones for gun shooters that work like this; they were linked to from a halfbakery idea.
I think this is adequately described. Since the microphones and speakers are in place, it's pretty much a software problem.-- spidermother, Jan 01 2009 I would cancel my neighbors barking dog.
An ignore-a-person setting would be cool. While hearing everyone else at a normal or amplified setting, just completely block sound whatsoever from whomever has a undesired mouth.-- Sir_Misspeller, Jan 01 2009 Bad science-- notexactly, May 01 2019 Well, better than nose cancelling headphones.-- not_morrison_rm, May 01 2019 I don't think so. I think the idea considers noise and wanted sounds to occupy non-overlapping frequency bands, and existing noise-canceling headphones to be able to magically identify which frequencies contain which type of sound. My understanding is that they usually work by trying to cancel all external sounds, but I could be wrong about that.
I'm not sure what you mean about the mute button. Function generators commonly have buttons (or knobs) to reduce the output amplitude by (up to) 10, 20, or 30 dB, but this is considered "attenuation" rather than "muting". Doesn't the mute button on a TV or radio just disable the audio output entirely?-- notexactly, May 02 2019 I foolishly didn't expect you to turn the exact function of mute buttons into a political/social issue…-- notexactly, May 02 2019 random, halfbakery