A foldable electronic device includes a first and second housings foldably coupled through a hinge, a flexible display supported by the first and second housings, a first speaker disposed in the first housing and a second speaker disposed in the second housing. The electronic device determines first and second states in which the first and second housings unfolded or folded. The electronic device controls sound frequency characteristics of the first and second speakers to have first sound frequency characteristics with the electronic device being in the first state. The electronic device controls sound frequency characteristics of the first speaker to have second sound frequency characteristics with the electronic device being in the second state. The electronic device may also control sound frequency characteristics of the second speaker to have third sound output frequency characteristics with the electronic device being in the second state.