There are many locations on Alcatraz that paranormal investigators think of as "hot spots." Many lean towards the prison hospital, I also think that the library is another strong activity point.
Last year I was on an overnight at the prison and I left a recorder alone inside the library, not many visited during this overnight, so I found it a good spot to leave the recorder. The results are, interesting to say the least. I won't spoil it to tell you which ones intrigued me the most, as I created the video so listeners can first make their own guesses as to what is being said, and then afterwards, I offer my own thoughts on the findings.
Take a listen and let me know what you hear. There are 7 different EVPs and some are short and a few are long (have a number of words). Sometimes not even being around, you can capture all kinds of things on your recorder that you maybe wouldn't have if you or others were around. Try this out sometime, you may be surprised by the results.