Microsoft Windows 10 comes with two text-to-speech engines or voices which vary for different language versions of Windows. For example, the US English version of Windows 10 comes with Microsoft Zira and Microsoft David voices. These voices can be used in Microsoft apps and desktop applications. But Microsoft also uses two separate voices for Cortana which again vary for various language versions of Windows. In case of US English version of Windows 10, Cortana uses Eva and Mark voices. These voices are not available for any other application except for Cortana itself. But with a little modification of the Windows Registry you can enable these voices for all the other applications as well.
In order to enable these hidden TTS voices for all the applications in Windows 10, you have to add a few entries to the Windows registry. To make things easier, you can just download enable-eva-mark-voice-windows10.zip, extract the contents to a folder and double-click on the REG files inside. The Eva Voice Windows 10.reg file enables the Eva voice and the Mark Voice Windows 10.reg enables the Mark voice in Windows 10.
After enabling these new voices, you can open Control Panel and choose the default voice. You can press the Win+X and select Control Panel from the menu. In the Control Panel, search for “speech” and then click on the Change text to speech settings. In the window that opens, you can choose a default voice from Voice Selection list-box and then finally click on OK button.
Conclusion: You can easily enable Microsoft Mark and Microsoft Eva that are hidden inside Windows 10’s Cortana files. By enabling these extra voices, you will be able to use them in all the other desktop applications.