QAudioOutput notify() signal doesn't work on android

On Android the notify() signal of QAudioOutput doesn't work. I have try with two devices with Android 4.
I set notifyinterval about 125ms.

(iStream is a QAudioOutput* object)

iStream->setNotifyInterval(125);
qDebug()<<"notify interval: " +QString::number(iStream->notifyInterval()); //I check and notify interval is 125 (all right)
connect(iStream,SIGNAL(notify()),this,SLOT(blockDone()));

This code works on Linux but on Android blockDone() is never called.

Regards