- mixer->get_audio_mixer()->set_audio_level_callback(bind(&MainWindow::audio_level_callback, this, _1, _2, _3, _4, _5, _6, _7, _8, _9));
+ mixer->get_audio_mixer()->set_audio_level_callback(bind(&MainWindow::audio_level_callback, this, _1, _2, _3, _4, _5, _6, _7, _8));