Sound

I’ve had my iPhone for over a year now. my sound has always come out of my speaker towards the top of my iPhone (by the forward camera) and out of one of the sides of my speakers at the bottom. it has never came out both sides of the speakers on my iPhone though. Now it is not coming out of either of the bottom speakers and is only coming from the top one. Is it something i can change in the settings or do i have to go to a store for it? i’m not very happy at the moment.