Why is there no audio coming out of my phone?

The audio on the phone could be on mute. to fix this go to "Apps->Settings->Sound->Volume" and make sure that all the levels are on the highest setting. Now make sure that there is nothing in the head phone jack, there could be head phones in the jack. If the jack is clear then the problem could be due to a software malfunction, try restarting the phone by holding the power button and waiting 10 seconds before restarting it. If the problem still persists then you'll need to replace the speakers. Rifer to Samsung Galaxy Prevail 2 Troubleshooting for more information.