Is it possible to process two microphones input in real time using DSP Toolbox??

I have been trying to implement active noise cancellation system using dsp system toolbox. I have used the dsp.AudioRecorder and AudioPlayer as well. Here is my initialization code.

mic_reference = dsp.AudioRecorder('NumChannels',1);
mic_reference.DeviceName='ASIO4ALL v2'; 
mic_error = dsp.AudioRecorder('NumChannels',1);
mic_error.DeviceName='ASIO4ALL v2';
sink1_2 = dsp.AudioPlayer;
sink1_2.DeviceName='ASIO4ALL v2';

when I call step(frame) for each of the microphone. I am getting error saying that

'Error using AudioRecorder/step A given audio device may only be opened once.'

Is it the limitation of dsp system toolbox to be able to operate only one audio recorder device at a time? or is it possible to use two audio recorder devices at a time ?

There is a provision for multichannel processing of the same audio device but how to process the audio from two independent devices in real time ?

Answer 1

[Walter Roberson]

You used the same device name for both of them. You need to distinguish the devices.

http://www.mathworks.com/matlabcentral/answers/114717-select-devicename-for-dsp-audiorecorder-and-dsp-audioplayer

[sai charan bandi]

After connecting two microphones and two headphones(using in built sound card and external sound card), I can only find 'ASIO4ALL v2' for tab completion for mic.DeviceName =' (Infact for all audio devices I create I am getting same device name!!)

I tried to use devinfo command like in the thread you mentioned but I am only getting the following output.

    >> ddevinfo=dspAudioDeviceInfo

ddevinfo =

          name: 'ASIO4ALL v2 (ASIO)'
     maxInputs: 2
    maxOutputs: 2

How can I access the individual device names ??

Note: I did change my audio driver from 'Windows Direct Sound' to 'ASIO' using preferences..> DSP System Toolbox

[Walter Roberson]

Sorry this does not appear to be documented.