I will try to explain my problem, when i use the code of the tutorial all work correctly:

connect (probe, SIGNAL (audioBufferProbed (QAudioBuffer)), this, SLOT (Processed (QAudioBuffer)));
probe-> setSource (Audiorecorder);
audioRecorder.record ();

The problem is that i want to change the size of the buffer, the buffer have only memory for 40ms. Someone could help me?

Thanks, It's an error, i translated the slot name!