Most screen readers will give you several 'voices' to choose from. You can modify the voice in several ways, e.g adjusting the speed, pitch and so on. This is useful. If you want to listen to a piece of text you may prefer to have the punctuation turned off. On the other hand, if you're correcting some text you may want all the punctuation read out to you so that you can edit for syntax.
Screen readers are unable to know in advance the pronunciation of all words.
As a result some are read incorrectly. Using a pronunciation dictionary you can edit these so they sound as you want them. There are lots of products. Popular screen readers in the UK include offerings from Dolphin, Henter Joyce and Alva. JAWS is reckoned to be the most complete program at the time of writing.