For some. Everybody learns differently. I’ve been acting for many, many years and have learned my own preferred method. It may or may not work for other people. Some are visual, and internalize the words by staring at the page; some are auditory and need to hear them; some are kinesthetic and need to speak them. For the new actor, I would recommend trying a few different approaches and see what works.
Here’s my method:
I record my dialogue and the significant cues (i.e. the lines spoken by other characters preceding my own lines) on the computer. Then I separate my lines from the other dialogue using left and right stereo channels. Then I cut the audio file into 2-3 minute chunks.
Then I drop the audio onto CD. I do one CD that has all the short files back to back, i.e. the entire play. I also do a CD for each file separately. Then I start playing the CDs during my morning and afternoon commute, starting with the first CD containing the first small file.
That, therefore, is a repeating audio clip of just a couple of minutes; the repetition of a small sample is what helps me memorize. It would do me no good to listen to the whole play intact, because I need to hear a small piece over and over again. Once I’ve got a handle on that, I move on to the second CD, containing the second small clip. Then the third. Then I go back to the first and review. And so on. Eventually, I graduate to the CD containing the whole play.
It’s a little wasteful to blow a whole disc on 2-3 minutes of audio, but the repetition of the short clip is key. If I mess something up, I make a mental note and try to get it right, and I get a chance to try it again very quickly, instead of waiting through the whole play. Instead of the CD, it would be better if my car stereo had the ability to repeat a single track, or if I could hook in an iPod and repeat a file, but neither is available to me. So I make CDs.
I’m currently rehearsing for a show in which I’m playing the lead, and I have a fairly staggering line load, like I haven’t had in probably ten years. And yet I’m probably going to get off book before anybody except the woman with the three-line bit part. I can’t promise that this approach will work for everybody, but for me, it works like a charm.