VoiceThread is an application integrated with Canvas that allows users to create presentations, post comments, and share content. 

VoiceThread is a totally web-based application that allows you to place collections of media like images, videos, documents, and presentations at the center of an asynchronous conversation. A VoiceThread allows people to have conversations and to make comments using any mix of text, a microphone, a webcam, a telephone, or uploaded audio file.

In addition to a single user, a VoiceThread can be made by a group of users. Users can write (or doodle) on the media while commenting, can utilize multiple identities, and can choose which comments are shown in the slideshow.

VoiceThread is also a very simple method for adding audio to your presentation slides. You upload the slides into VoiceThread and use the easy audio tools to add your narration and comments.

The video below provides an overview of the VoiceThread tool:

Please see original article Using VoiceThread in Canvas