Iphone 6 upper or calling speaker problem

[gurdarsh]

I have iphone 6 and calling or known as upper speaker has very low volume while attending a call how it can be fixed

 

[kch50428]

Could be a hardware problem that would be covered under standard warranty or AppleCare - consider a visit to an AppleStore/GeniusBar for diagnosis of the issue and see what options are available to you.