Sprint Galaxy S4: Why doesn't volume rocker work during call with phone to ear???

[Huff]

Depending on ambient noise its often necessary to adjust volume while on a call. Only way to do that is to remove phone from ear so screen comes on then use rocker or slider. Why cant I use rocker while still talking with phone to ear?? All prior phones could do this. Pain!!

 

[84guy]

Never realized this. It does suck tho

Sent from my Sprint Galaxy S4

 

[B. Diddy]

This happened with my old Razr Maxx as well. Not sure if it occurs with my Nexus 5, but I think it does.

 

[Gordan Simovski]

So any solution on this? I have the same problem, and everything else is working fine on the phone...