What should I do if there is no sound in the iPhone 6?
Do not immediately run to the service center and take the device for repairs, spend your money and precious time. The problem can be in the phone settings, so I'll give you an article below that has already helped solve the above problem for many iPhone users.
Then proceed according to the instructions:
If these manipulations lead nowhere, the problem is more serious and lies in the device itself.
Well, first you need to check all the settings and make sure that the sound is turned on at all. If the sound does not appear, you can turn the phone on and off in Russian. If this did not help, then the road to your service center.