You may access Act 4, Scene 3 to read and listen to the text:
http://etc.usf.edu/lit2go/215/the-tragedy-of-macbeth/5571/act-4-scene-3/
You may also watch a short clip from this scene:
http://etc.usf.edu/lit2go/215/the-tragedy-of-macbeth/5571/act-4-scene-3/
You may also watch a short clip from this scene: