Due to recent security updates in Chrome you will need to allow the blocked plugin everytime you attempt to preview a background audio file in Brainshark. To avoid this you can choose to do the following:
Type chrome://flags in your address bar. Then find Run all Flash content when Flash setting is set to "allow" Mac, Windows, Linux, Chrome OS For sites that have been set to "allow" Flash content, run all content including any that has been deemed unimportant. Set the flag to Enabled. Restart your browser.
We recommend you contact your IT team to avoid any breaches with their security policies.