White Noise Sound Attenuation

white noise is a random noise in the signal of any kind. It has uniform frequency spread and hence can be seen in each channel of communication, amplifier, numbers. However, any kind of mathematical generator of number will have some correlation and is never purely white noise.

In a speech audio scenario (which is analogue) many noise generators (even pseudo noise (PN) sequences) will work. It is very easy to generate white or Gaussian noise from a simple analogue circuit and amplify it. It is very easy to generate, using simple digital logic, PN signals with very very long repetition periods.

If either is presented as amplified audio it would do the trick (of reducing the audio signal to noise ratio), and if there is risk of interception, recording and post-processing, the "seed" for the PN sequence can be changed at intervals far less than the repetition period.

No, not attenuation but diminution of signal to noise ratio.

Drill here

http://www.google.com/search?hl=en&q=%22white+noise%22+%2Bmasking

Looooong ago, as a Junior, I worked for a big outfit which had an open
office plan and white noise sound attenuators actuated by occupancy sensors.

As I often worked late, I had the unique experience of being followed every
time I went to get a document or take a coffee or kidney break by an annoying,
puzzling whooshing sound.

Even after discovering what it was, the paranoia lingered. -
Remember all those 'B` horror movies where the lone guy working late gets it?

Speech is a wideband acoustic signal generated by the periodic vibration of the vocal chords (voiced sounds) and fricatives (hard sounds like k's t's etc). This wide band signal is modulated by the speaker changing the shape of the vocal tract with the tongue, larnyx, etc.

In short, white noise does not attenuate anything but is a wide band signal (all frequencies) that basically covers up the speech signal. It is quite effective in masking voice and is commonly used in secure areas to prevent eavesdropping. (In spy movies, I think they turn on the shower). I have a white noise wav file I play through my headphones when the office gets too noisy and I need to concentrate.

I don't know if this answers your question.

Use "wet noise" if they get too noisy. It comes froma hoze

Playing white noise to avoid room chatting noise is very interesting one. I also like that wet noise idea. Some one made music out of different car engine noises, I have see that in Guinness Book of world records series.

In India there are many people who can separate talk for 100 people chatting in a room and can put down on paper of what all have said for each one separately. I do not know how they do it, but all that is a noise for me.

There is some amazing signal processing that gets done between your ears!