Praise Audio

There are some things I can tell students in an email. But sometimes, I feel the need to use audio to convey my message. A case came up this week. I was at a conference and my students were posting their work asynchronously in WebCT. Their work was good, and I wanted them to know it. How best to communicate praise? I chose to speak my praise and sent it to them as an audio file. I hope they listened and understood, from my words and my tone, how very impressed I was with their work.