If you want an idea of what the plays sounded like at the time they were written, check out the work by David Crystal in his efforts to reconstruct Original Pro

If you want an idea of what the plays sounded like at the time they were written, check out the work by David Crystal in his efforts to reconstruct Original Pronunciation (OP). There are YouTube videos of him and his son (Ben Crystal) talking about this and giving sample readings. They can do this by several methods. You can compare rhymes in the works -- e.g. loved and proved rhymed. You can study what people at the time documenting pronunciation wrote. You can compare existing accents to uncover ways in which pronunciations of words have evolved and diverged. You can apply and reverse sound changes in the words, such as reversing effects of the Great Vowel Shift. Doing this gives some interesting puns and plays on words that are not readily apparent when reading the plays with modern accents. The OP accent has elements from other accents, as those have retained some of the historic qualities. For example, OP is a rhotic accent (the Rs are pronounced) which is a feature that is present in several modern accents like Scottish, American, and parts of England.