Text-to-speech within Dictionary Chrome's extension isn't working

When you open a popup translation by double-clicking on a word, along with it appears a speaker icon for listening to the pronunciation but clicking on it nothing happens.

Comodo Dragon Version, no theme installed, no other extension installed (except for Share Page Service and Web Inspector)
Windows 7 Ultimate 32bit fully patched, UAC enabled with default setting. CD is installed on “C:\Program Files\COMODO\Dragon\dragon.exe”, Windows on drive C:.
Chrome isn’t installed. CD is run either on administrative account than on limited user account.

Sorry for my bad english…
Best regards