How can I easily test sound (speakers and Mic) on my ipad? I do a lot of webinars and sometimes ipads viewing the webinar have sound problems.

I'm looking for a really easy way for them to test their speakers and mic.
(Speakers are relatively easy to test, and often very commonly used, so it's more obvious (to them) if they aren't working.)  But would be good to test both at the same time.

Thanks!
Take a video of anything (yourself, your pets, traffic, etc.)  and while recording, say something.  Replay the video.  If you hear the sound you are supposed to, it works. 

This has the benefits of testing both at the same time and ruling out hardware issues should you run into difficulties during the webinar.