SoundCloud is a sound sharing platform that you can use to capture a voice, moment or music in seconds or upload audio you’ve already created. The premise behind this service is that everyone has sounds to share and now you can share yours.
Some PowerPoint Presentations may afford to have a background sound clips or music during the Slideshow, however some other presentations may not afford this kind of sound because can disturb your audience or your public speech. However, if you are in the case where you can place a sound or music in your powerpoint presentation, for example to prepare a demo powerpoint presentation or virtual tourist guide, then SoundCloud can be really handy to find sound clips and music.
You can open SoundCloud and look for the Creative Commons sound clips for your presentations. http://soundcloud.com/creativecommons
For example you can download this sound clip.
Here you can click on Download and then download the mp3 version of this selected sound. Now you can go to powerpoint and Insert the Audio File. powerpoint in Windows will allow you to insert mp3 files so in this case it will work pretty straightforward. If you have any other format and need to be converted, you can consider to use a sound conversion tool.
Now you can preview the sound in powerpoint.
Learn more in http://soundcloud.com/creativecommons