<http://schema.org/description>
"Google is working on identifying Chrome tabs that are currently playing audio (or recording it). The feature is expected to show an audio animation if a tab is broadcasting or recording ..."^^<http://www.w3.org/2001/XMLSchema#string>
<http://thenextweb.com/google/2013/02/25/google-chrome-may-soon-get-audio-indicators-to-show-you-noisy-tabs-keep-them-open-when-memory-runs-out/?_escaped_fragment_=sUx8i>