Your iPhone Volume Could Be Turned Down On the side of your phone, under the Action button or Silent switch, you'll find the Volume buttons, which adjust sounds for videos and music in increments.

Having trouble hearing what someone who called you is saying? The cause could be any number of issues with your iPhone, but you may be able to fix it yourself.

Use the volume buttons on the side of your iPhone to increase the sound, especially while using apps that produce audio, to verify they aren’t muted. Diving Into Software Settings ...