"White Noise" Sound feature!

[Reece]

      If your like me and love having noise canceling head-sets/white-noise, but don't want to pay the extra $$$ to get one, wouldn't it be great to have a noise canceling/white noise feature build in to an mp3 device?!
    Basically, under Settings/Sound settings/     there would be an option for "White Noise." If you turn it on, it would run a white sound loop over the external speakers/headphones. It would run during any application, music, or game. And can only be deactivated by going into the settings and turning it off, or (of course) turning off the player. That means it will run during any feature of the device, even Doom, which usually turns off music when started. I am sure there is a way to get it to run in the background while audio is playing.

     As an extra, you could even choose the type of noise; such as White, Brown, Pink, and so on.
(Yes there are color coded sounds. I like White, Brown, And Blue noise the best )
There could even be a condition setting. So if there is a feature of the device you don't want it to run in, for instance, the radio, you can just set it to turn off whenever you activate the radio, and turn back on when the radio is turned off.

( Excuse the obviously un-revised writing, I am in a hurry (Again)  )

[Reece]

NOTE: There could be the feature to add your own loop file to play in the background.

[wodz]

I don't get your idea, You want to mix actual music with white/pink/whatever noise? What for?

[Reece]

        Noise-cancelling headphones are headphones that reduce unwanted ambient sounds. When you buy a pare of "Noise Canceling" headphones, and turn them on, they make a soft "shhhh" sound. Normally the sound is made by the headphones using an "antinoise" signal," which is basically soft static. but many devices just use seamless white noise loops instead ( Listen here: http://www.youtube.com/watch?v=1KaOrSuWZeM: ) It decreases the outside noise, while making your music/audio-books sound better. The sound the headphones make is white noise. And all you need to make your headphones noise canceling is to play white noise on them. So if you have the mp3-device play white noise in the background, it will make your listening experience allot better. And white noise is very faint, and does not interfere with the audio quality of your music, it enhances it. And you can always choose to turn it off.


Here is a quick clipping from wiki:
(It may explain noise cancelling better than I can.)


     Noise cancellation makes it possible to enjoy music without raising the volume excessively. It can also help a passenger sleep in a noisy vehicle such as an airliner. Research examining the benefits of noise cancelling headphones in the aviation environment has found that compared to passive noise attenuating headphones or no headphones, noise cancelling headphones significantly increases the signal to noise ratio, making hearing important information such as safety announcements easier.  The benefits of noise cancelling headphones also extend to situations involving concurrent task (dual task) performance such as completing a maths based task (e.g., Sudoku) as well as listening task.
Noise-cancelling headphones typically use ANC to cancel the lower-frequency portions of the noise; they depend on more traditional methods such as soundproofing to prevent higher-frequency noise from reaching the ear. This approach is preferred because it reduces the demand for complicated electronic circuitry that would be required for noise cancellation at higher frequencies, where active cancellation is less effective. To truly cancel high frequency components (coming at the ear from all directions), the sensor and emitter for the cancelling waveform would have to be adjacent to the user's eardrum, which is not technically feasible.

(Hope this helps)

EDIT: Brown, Pink, Blue ect... Those are just extra types of soft randomized sound just like white noise. But they do not work near as well with audio as white noise does.

EDIT(2): I found this wiki all about white noise:   http://en.wikipedia.org/wiki/Colors_of_noise

[wodz]

Maybe I am missing something but from my limited signal processing knowledge it should be 'noise' in reverse phase to the ambient noise (which is not exactly white noise). I heard of systems doing online FFT and artificially generating anti-phase noise to do noise cancellation but this is much different to simply mixing with noise.

[Reece]

Maybe I am missing something but from my limited signal processing knowledge it should be 'noise' in reverse phase to the ambient noise (which is not exactly white noise). I heard of systems doing online FFT and artificially generating anti-phase noise to do noise cancellation but this is much different to simply mixing with noise.

Can you re-phrase that? I don't quite understand what you are asking.
Sorry...

[wodz]

My point is that noise cancellation is much more then simply mixing with white noise AFAIK.

[Reece]

      There is no technology out there that digitally (truly) cancels out all sound. Accept by means of physical features such as specialty glass and such, but I am talking about digital cancellation. The white noise cancels out all low frequency sounds. And yes, it is that simple. Noise canceling headphones have one or more microphones, and electronic circuitry which uses the microphone signal to generate a random "antinoise" signal. When the antinoise signal is produced by the speaker in the headphone, destructive interference (the white noise AKA antinoise) cancels out the ambient noise as heard within the enclosed volume of the headphone.

So all we have to do, is to utilize the built in mic in most players, to generate the antinoise signal. There fore canceling out low frequency/ambient noises around you, enabling you to hear your music better.

EDIT: And of course you have to have decent speakers/headphones for it to work well.
         Its a great option to have...

[saratoga]

If you want white noise, just convert all your audio files to 8 bit.

No need to add noise when you can just lower the bitrate on your files

[[Saint]]

At least the thread is aptly named.

By my understanding, this method is not noise cancellation at all...wodz describes it best. Noise cancellation is actively adapting to the situation at hand, mixing in the required amount of anti-noise for the situation, rather than mixing a predefined amount of  white noise (which is different to anti-noise) with the audio. Otherwise known as active noise control. Passive noise control, by my understanding, uses only dampening/muffling of ambient sounds and does not attempt to cancel it by adding an anti-noise singal.


[Saint]

EDIT: Perhaps some of the many fine products listed here can banish the unwanted noise from your audio system before it is even created.

[wodz]

So all we have to do, is to utilize the built in mic in most players, to generate the antinoise signal. There fore canceling out low frequency/ambient noises around you, enabling you to hear your music better.

So it is NOT white noise but something quite different as I said. Anyway no single target running rockbox is able to record and playback at the same time so this is technically impossible to implement.

[monoid]

Another problem, even more serious, is that microphone should be close to the head, or at least unobstructed. And another problem, at least for HDD players is the sound of spinning HDD captured by mic...

[Reece]

         Dang. Well the odds agents this are overwhelming, I guess it won't be possible. Oh well, it was worth a shot.

[[Saint]]

Your original idea is entirely possible.

The main bulk of replies here were just to make sure that you weren't confusing mixing in a predetermined level of white noise into the audio with noise cancellation, which it is not. Your idea is possible, true active noise cancellation, is not.


[Saint]

[Reece]

  Ahh... I get it now. Thanks for the clarification.