The Google Now Voice search is not talking back on my Nexus 7. When I use Google Now on the wifi at work, it listens to me, speaks "Recognizing..." for 6 seconds, then just goes back to "Tap mic to start speaking." I have tried changing the language from UK to english (US) and still no speak replies, including weather.
That's a firewall issue with that. The service's IP and ports are blocking by firewall on our work network. After I add a rule to the firewall to the connection, Google Now works perfectly on my tablet.
Destination ports: 5228 and 14259. 5228 is needed for push notifications.
Google server IP: 184.108.40.206 and 220.127.116.11.