iPhone 7 Speaker problem¿

I have the iPhone 7 and i’ve been having this problem where if my phone is on hand held mode, the top speaker works but the bottom left speaker doesn’t but if i turn my phone upside down the bottom left speaker works and the upper speaker doesn’t? Can anyone please help I’ve been searching almost everything And i tried it it still doesnt work can anybody help? I have the newest OS The iOS 12.1. Even if i use earphones i can only hear it from either the left or the right side of the earphone