Q: Sound not working!!!

Is your isight microphone covered by a case or protective film?

Get help with the microphones on your iPhone, iPad, and iPod touch - Apple Support

Did you already try the general troubleshooting steps?

1. Force restart the phone by holding the sleep and home button for about 10sec, until the Apple logo comes back again. You will not lose data.

2. In case this does not work, set it back to factory settings, without using the latest backup. Test the phone. If it works, restore from the backup.

3. If factory resetting does not help, get the phone checked by Apple:

Start a service request

Find an Apple Authorized Service Provider

Make an Apple Store appointment