Hi, I'm nagachika from Japan. I'm glad to find who interested in audio frameworks in this ML! If what you want is just play audio format file, using NSSound may be easiest way to do it. I'm just trying to use CoreAudio framework with MacRuby to control audio devices. I can get/set some property of audio devices. For example get audio devices list and change sampling rate of them. But I cannot output waveform data to audio output device. It seems than Proc registered as callback function isn't called. I just want to file a ticket about it. BTW, I would like to try use AudioUnit framework via MacRuby. AudioUnit has no BridgeSupport file in system directories. But I found 'gen_bridge_metadata' recently, I think MacRuby can use AudioUnit too. Best Regards,