//Instantiate Prsentation class that represents the PPTX
Presentation pres = new Presentation();

//Get the first slide
ISlide sld = pres.getSlides().get_Item(0);

//Load the wav sound file to stram
FileInputStream fstr = new FileInputStream(new File("logon.wav"));

//Add Audio Frame
IAudioFrame af = sld.getShapes().addAudioFrameEmbedded(50, 150, 100, 100, fstr);

//Set Play Mode and Volume of the Audio
af.setPlayMode(AudioPlayModePreset.Auto);
af.setVolume(AudioVolumeMode.Loud);

//Write the PPTX file to disk
pres.save("AsposeAudio.pptx", SaveFormat.Pptx);