Not from memory, you just have to get the context right as to what is the purpose of the speech, who is the audience, how does the orator use rhetoric to further his/her points. I managed to get a 19/20 for my speeches essay without the need for critical material.
BUT, if you really want to use critical material, be sure not to detract from actually analysing your speeches, i.e. use the critical material as a way of introducing your arguments or perspectives (you might not agree with the speeches' mesage and how effective it is and using critical material strengthens your perspectives).
