Audio Frequency White Noise generation using Arduino Mini Pro
I don't know that you need all that - just an Arduino and a piezo speaker and a pot if you want to play with the volume.
void generateNoise() {
    unsigned long int newr;
    unsigned char lobit;
    unsigned char b31, b29, b25, b24;
    b31 = (reg &amp; (1L &lt;&lt; 31)) &gt;&gt; 31;
    b29 = (reg &amp; (1L &lt;&lt; 29)) &gt;&gt; 29;
    b25 = (reg &amp; (1L &lt;&lt; 25)) &gt;&gt; 25;
    b24 = (reg &amp; (1L &lt;&lt; 24)) &gt;&gt; 24;
    lobit = b31 ^ b29 ^ b25 ^ b24;
    newr = (reg &lt;&lt; 1) | lobit;
    reg = newr;
    digitalWrite (speakerPin, reg &amp; 1);
    delayMicroseconds (50);  // Changing this value changes the frequency.
}