I was wondering if anyone knew of a way through Processing to play audio though the speakers as it comes in through the mic.  Basically, whatever comes in the mic is played back realtime.

Thanks!

Well, check for a few things:

When sound comes through a mic, most OS default play it to speakers: check your volume levels, and look for a "Microphone" sound level, adjusting this will let you do what the program above does ... without having to

Or, check that your selected "Input source" is actually the mike: if you've selected stereo out, than you'll be writing out to a stream that you're reading: which results in lots and lots of feedback. (but that doesn't sound like what you described)

hmmm can you give us more symptoms?

I had some trouble running the above code, so I looked at the Waverender code on the minim site
http://code.compartmental.net/minim/examples/Recordable/addListener/waveform.pde

and pieced that code together with the code in the post.

My main goal was to get my line-in on my Mac (I plugged in a microphone) to play through my Mac speakers using minim.  Thus, this code connectes AudioInput to AudioOutput in Minim.

Code:

import ddf.minim.*;

Minim minim;
AudioInput in;
AudioOutput out;
WaveformRenderer waveform;

void setup()
{
  size(512, 200, P3D);

  minim = new Minim(this);
  minim.debugOn();

  // get a line in from Minim, default bit depth is 16
  in = minim.getLineIn(Minim.STEREO, 512);
  out = minim.getLineOut(Minim.STEREO, 512);

  waveform = new WaveformRenderer();
  in.addListener(waveform);


  // adds the signal to the output
  out.addSignal(waveform);

}

void draw()
{
  background(0);
  stroke(255);
  // draw the waveforms
  for(int i = 0; i < in.bufferSize() - 1; i++)
  {
    line(i, 50 + in.left.get(i)*50, i+1, 50 + in.left.get(i+1)*50);
    line(i, 150 + in.right.get(i)*50, i+1, 150 + in.right.get(i+1)*50);
  }
}


void stop()
{
  // always close Minim audio classes when you are done with them
  in.close();
  out.close();

  minim.stop();

  super.stop();
}


class WaveformRenderer implements AudioListener, AudioSignal
{

  private float[] left;
  private float[] right;

  WaveformRenderer()
  {
    //    left = null; 
    //    right = null;
  }

  synchronized void samples(float[] samp)
  {
    left = samp;
  }

  synchronized void samples(float[] sampL, float[] sampR)
  {
    left = sampL;
    right = sampR;
  }


  void generate(float[] samp)
  {
    System.arraycopy(right, 0, samp, 0, samp.length);

  }

  // this is a stricly mono signal
  void generate(float[] sampL, float[] sampR)
  {
    if (left!=null && right!=null){
      System.arraycopy(left, 0, sampL, 0, sampL.length);
      System.arraycopy(right, 0, sampR, 0, sampR.length);
    }
  }


}