If you press the volume buttons, but the sound won't turn up, open the Settings app and click Sounds & Haptics Confirm that the switch next to Change with Buttons is turned on; Press and hold power/sleep/wake button on your iPhone till slider screen appears Now slide the slider to right to turn off your iPhone Now, once again press and holdIn this video, I show you how to fix the iPhone speaker problem that is causing no soundSome of the symptoms
Iphone 7 Speaker Not Working Solution Youtube