Apple Macintosh and iPad users can use the Apple Keynote presentation to open and view Microsoft PowerPoint presentations saved in PPT or PPS format. Differences in the way these applications save and process audio content, though, can leave Keynote users frustrated with an apparent inability to hear sounds that the PowerPoint presentation contains.
PowerPoint users have several options for inserting audio into a presentation. To insert audio, users must select a slide for the audio content, click “Insert” and select the appropriate audio file. PowerPoint offers users an array of options for inserting the file, including the option to import the file into the presentation or link to the external audio file. Keynote handles audio content in a somewhat different manner, though. To insert audio into a Keynote presentation, users simply drag the audio file onto the corresponding slide; Keynote automatically embeds the audio file for playback during the presentation.
Linked versus Embedded
When PowerPoint users insert audio into a presentation and elect to embed the audio file, PowerPoint imports the audio file for inclusion. The software processes the file and incorporates it as a part of the PPT or PPS file in much the same way as Keynote handles audio imports. When a user chooses to link to the audio file rather than embed it, though, PowerPoint creates a reference to the external audio file rather than importing it.
Because PowerPoint includes embedded audio in the PPT or PPS file, the embedding option allows users to distribute a single PowerPoint file that includes sound. According to Apple, Keynote can typically open, interpret and replay this type of content. When a user links to an audio file rather than embedding it, though, PowerPoint does not incorporate the linked audio into the PPT or PPS file. Because Keynote handles audio by embedding the audio file, it may not properly process linked audio files. In addition, PowerPoint presentations containing linked audio require that the linked audio file accompany the presentation. If the audio file does not exist on the viewer’s local computer, the link becomes broken and the audio will not play back.
Users who cannot hear music during the PPS playback should verify that the computer or iPad’s volume is turned to an audible level and not muted. In some cases, formatting differences between PowerPoint PPS and PPT files may cause Keynote to not recognize some content; a number of file conversion utilities allow users to convert PPS files to Keynote-compatible presentations. In addition, Keynote users may be unable to play back audio if the PPS file becomes corrupt during download or transfer.