This application is not free. However, you can download a free trial version to test it yourself. The free version will pronounce only 200 words, after that you will have to decide whether you want to buy it or not.
One thing I have noticed about this software, is that it supposedly allows you to change the language it works with. When you change it from English to Spanish for example, all the interface will change, but when you click on the speak button, you will notice that the pronunciation on the other language is terrible. It only works fine in English. Nevertheless, there is a nice feature that will let you change the pronunciation of a specific word.
Text Speaker 3.1 lets you set hotkeys to make the program easier to use.