Audio files supported within the online powerpoint/presentation viewer must be in a compatible format. For example, '.wma' files are not compatible, but '.m4a' files are. Within Microsoft Powerpoint you can optimise the '.pptx' file so that all media within it will work on FolensOnline within the online viewer. To do this, click File then Info. Then, click the Optimise Compatibility button:
You can then save this file and upload it to your FolensOnline resource bank.