What icon do you use to indicate interaction?

Hello everyone, just wondering what icon anyone else uses on their sites to show a link to their SCORM packages for student learning activities. At the moment we use:

• audio files a headphone icon
• video a play button
• external reading a book icon

However, some of the Storyline files we use do not have sound and aren't videos so we are struggling. Sometimes students go past the link and don't click on it so we want to make them stand out as interactive activities.

Or are we overthinking? There doesn't seem to be a standard 'multimedia/interaction' type icon...or is there?

Thanks for any advice!