Follow the steps described here precisely to enable Eva on your Windows. However you can configure to include “Windows Eva Mobile” voice which sound more natural and comfortable to listen to. But the default Text-to-Speech for Windows desktops version are very robotic and monotonous. You can choose from multiple default voices provided from Microsoft as default TTS voice. On the Tools menu, you should find a Start Text to Speech option to start the recitation of your book with default Text to Speech voice on your Windows. Once installed open up any book of your choice. Download it directly from the Amazon download site and you are ready to enjoy your books on your Desktop, Laptop or Windows Tablet. You will need the latest Kindle app from Amazon to enjoy Text-to-Speech feature.
However, the Kindle app on Windows still needs to be in the foreground for continuous recitation. You can still use TTS on iPad or iPhones by using iOS accessibility service. Amazon only allows Text-to-Speech features on their own Kindle and Windows application.
While it isn’t as customizable as the Android or iPhone offerings, it does allow in-built TTS to read out your books. Kindle for Windows allows you to read all your library on Windows operating system.