Building a stable noise generator for audio-frequency purposes requires only a few components. This circuit relies on linear-feedback shift registers and some simple software.
http://www.edn.com/article/CA313057.html
Trying to find a single IC noise source can be frustrating. You could use a single-chip microcontroller, such as Microchip 12C508 for this application. This article gives you idea and software how to do that.
http://www.edn.com/article/CA200385.html
http://www.web-ee.com/Schematics/Pink%20Noise/pink.htm
http://www.web-ee.com/Schematics/Noise%20Generator/noise.htm
http://www.web-ee.com/Schematics/Random_Bit_Sequence/RBS.htm
http://www.web-ee.com/Schematics/TinyWhiteNoise/TinyWhite.htm
Producing crypto-quality randomness in a computer is a perennial issue in cryptography, here are some ideas
http://world.std.com/~reinhold/truenoise.html
you can double the speed of a standard pseudonoise (PN) generator by using additional exclusive-OR gates and a fast 2:1 multiplexer
http://www.edn.com/archives/1994/122294/26di1.htm