How to Embed mp3 Sounds
Most places will tell you that only wav files can be embedded in powerpoint. All other sound formats are linked. Since mp3 files can be 10 x smaller it would be very useful if you could embed them. Linked files can cause problems .
You can and here's how:
The technique is to add a header to the .mp3 file that will convince PowerPoint that it is actually a wav file. Although this will change the file name to "something.wav" the file remains an mp3 file, the same size as the original and will play in PowerPoint as an mp3 file. NOTE this only seems to work with PCs not with Macs.
You will need to download a free program called CDex to add the header. You can get it here CDex. The download page is a little confusing but the file you need is the windows exe version (cdex_170b2_enu.exe)
With CDex use "Convert > "Add a RIFF wav header to mp2/mp3" to produce a file that will be virtually identical to the mp3 file but will have the .wav suffix and can be embedded using either of the techniques in Embedding Sound Files. The headered file should be found in the same folder as the original mps file.
If you are starting with a wav file and want to coonvert it to mp3 to reduce it's size then CDex will do this too. Choose convert > WAV files to Compressed Audio. Before you do this check Options>Settings > Filename tab and make sure you know where the converted file will be saved!
Many people speak of RIFF wav files as a special type of wav file. This is not the case RIFF stands for "Resource Interchange Fle Format" and applies to all wav files . You have not converted the mp3 to a RIFF wav merely convinced PowerPoint that the mp3 IS a normal wav file. RIFF wav has however slipped into technically incorrect common usage to mean an mp3 file with a wav header.