Why is the volume on my earpiece so low on my iPhone 6 plus?

[iMore Question]

why is the volume on my earpiece so low my iphon 6 plus

I cant hear the caller talking barely

 

[Ledsteplin]

why is the volume on my earpiece so low my iphon 6 plus

Welcome to iMore! Make sure nothing is blocking the top speaker. It's in the center where there is a slit at the top. I got ketchup on mine once, and had trouble hearing. Realized what I had done and cleaned it. Works great now.
You might also try going to Settings > General > Accessibility > Hearing Aids > Toggle on Hearing Aid Mode. This has increased volume on some phones. YMMV
Make sure volume is turned up on the side of the phone, and in Settings > Sounds, and the volume control in the pull up Control Center.
Lastly, take it to Apple and let them look at it.