Select Site Info.
Select Site Info from the site's tool menu.
Select Manage Tools.
Select Manage Tools from the Actions Menu.
Select VoiceThread.
Scroll down the list of tools and check the checkbox for VoiceThread.
Select Continue.
Select Continue to apply changes.
Select Finish.
New tool added will be listed in red on a confirmation page. Confirm the addition of the VoiceThread tool by selecting Finish.