Reactive vs Interactive

The following is how I would describe the difference between interactive and reactive.

When an object is reactive it is a simple function where you give it an input and it will trigger a response. In this case you can have multiple inputs give you the same output which makes it so no matter how a person does something, they will always get the same reply. When an object in interactive it will respond to an input with an appropriate output. It is mutually active in its output because one input should equal one output. Each input should produce a different outcome.

An interesting segment I found on Ubu was about Panoramic Sound. 

http://www.ubu.com/sound/electronic_panorama.html