Welcome to the Samvacaka help page.
After clicking the "पठ्यताम्" button, the text is synthesized and it should start playing automatically. If it is not the case, try following steps.
The synthesized file is played using the default media player plugin of the browser. In Internet Explorer, Google Chrome or Mozilla Firefox browsers, a security alert pots up as a ribbon at the top or bottom of the web page. Left click on the ribbon and select the option which says to "allow the plugin to play the content". The sound should start playing.
If the security alert ribbon does not appear, or you have closed it after it appeared, then right click on the box below the "पठ्यताम्" button, and chose the option to "allow" or "always allow" the media player plugin to play the content.
If some media player plugin for particular browser is not installed, then you may need to install one (like VLC Media Player or Adobe Flash Player).
Specific to Google Chrome: if VLC Media Player is installed but the brwoser pops up to update or install some other media player plugin, it means the other plugin is default. Type "chrome://plugins" in the address bar, press enter. Now in the list of plugins, uncheck "Always allowed" box for the other plugin, and check such box for your preferred plugin.
If you still feel problem in playing the synthesized sound, please let us know on feedback page.