Hi, I have tried to write my own SoX effect to generate Gaussian white noise as an alternative to the uniform white noise that it generates currently. Even though I have a copy of "Numerical Recipes in C", a fair amount of C experience, and the internet at my disposal, I'm still stuck. Would anyone mind looking at the code I have come up with so far, and hopefully tell me where I am screwing up? A patch file for synth.c is attached; patch your v14.4.2 synth.c file with my changes using: cd sox-14.4.2/src patch -p1 = 1 || S == 0); X = V1 * sqrt(-2 * log(S) / S); } else { X = V2 * sqrt(-2 * log(S) / S); } phase = 1 - phase; } while (X < -1 || X > 1); synth_out = X; //printf("%lf\n", synth_out); }