# ofSignedNoise output as soundstream?

I am trying to use the ofNoise functions as a generator for sound to put it in the soundstream.
Based on the outputsound example i adjusted the sine generation a bit like following:

``````phaseAdder = 0.1;
for (int i = 0; i < bufferSize; i++){
//float sample = sin(phase);
lAudio[i] = output[i*nChannels    ] = ofSignedNoise(phase) * volume * leftScale;
rAudio[i] = output[i*nChannels + 1] = ofSignedNoise(phase) * volume * rightScale;
}
``````

This somehow works, but i get strange sounds out of it. not what i expected. how would you do this? What i want to do is later scale the noise frome white noise to a more low frequency wobble.

edit you are correct! sorry about that should have looked up the docs first

I think you are wrong. ofNoise stays between 0.0 and 1.0 and ofSignedNoise is between -1.0 and 1.0.
http://www.openframeworks.cc/documentation/math/ofMath.html#show_ofNoise
http://www.openframeworks.cc/documentation/math/ofMath.html#show_ofSignedNoise

But I think my main problem is in the implementation of the function.
I found out that I better set the phase size in setup. But i still getting a strange cyclic oscillating distorted oscillator and not a noise. How can i get an ongoing noise with variable waveform?

ofNoise or ofSignedNoise are simplex noise not white noise, if you want white noise you can just call ofRandom as is demoed in that same example

i forgot to mention that i am aware 8f this fact. this is of cause implemented in the example. but i really like to use perlin/simplex because of its characteristics. i dont really want white noise. hope this is understandable…

but perlin noise will sound like that since it has a certain periodicity. probably what you want is to modulate white nouse using a sine wave or something similar?

a certain periodicity is welcome, but the one i have is to periodic i think.
Check out this image:

Maybe i should look for a way to filter white noise with an bandpass. But i really like the idea of using the same algorithm in sound and image at the same time.

I think I am doing something wrong. Maybe someone can tell me if I understand the audioOut loop right.
I am increasing the phase value endless by my adder value. for example 0.1f so that the buffer loops should continue the noise waveform after every buffer loop.

``````//--------------------------------------------------------------
void ofApp::audioOut(float * output, int bufferSize, int nChannels){
//pan = 0.5f;
float leftScale = 1 - pan;
float rightScale = pan;

for (int i = 0; i < bufferSize; i++){
//float sample = sin(phase);
lAudio[i] = output[i*nChannels    ] = ofSignedNoise(phase) * volume * leftScale;
rAudio[i] = output[i*nChannels + 1] = ofSignedNoise(phase) * volume * rightScale;

}

}``````

perlin noise is always 0 at the integers so what you are seeing is correct

checkout the 1d periodic signals example in math to understand how noise and random behave in comparison with other waves. if you want something that sounds like white noise perlin noise is not the right choice

Hey Arturo, yeah I know that it will not sound like white noise. It can not! But for me it didnt has to. I was just a bit confused of the periodic character of the sounds i heard.
Thanks for the explanation about the noise characteristics. This makes it even more interesting. By the way. when you mix two perlin noises which are phase shifted and have different phase width, they almost sound like white noise.