An air pulse generating element (10, 1500, 1600) comprising: a front faceplate; a back faceplate; a front supporting element, connected to the front faceplate; a back supporting element, connected to the back faceplate; a folded membrane (110, 1510, 1610), configured to form a front chamber and a back chamber, and comprising a plurality of membrane units; wherein the plurality of membrane units are parallel and sequentially connected and an end of the folded membrane (110, 1510, 1610) is connected to the back faceplate via the back supporting element and another end of the folded membrane (110, 1510, 1610) is connected to the front faceplate via the front supporting element; a first wall (112_1), disposed along a first plane (P_1) corresponding to a side of the front supporting element with a first air flow channel (C_1) a second wall (112_2), disposed along a second plane (P_2) corresponding to a side of the back supporting element with a second air flow channel (C_2); and a plurality of valves (VFF, VFB, VSF, VSB) controlling the first and second air flow channels (C_1, C_2) between the front chamber toward either a front space or a back space, and between the back chamber toward either the front space or the back space; a plurality of actuators (122, 1522), each formed on a side of a membrane unit of the plurality of membrane units; wherein the plurality of membrane units are configured to perform horizontal deformation to squeeze air in and out of the front or back chamber with operations of the plurality of valves (VFF, VFB, VSF, VSB) controlling the direction of the air pulse toward the front space or the back space; wherein a first front valve and a first back valve of the plurality of valves (VFF, VFB, VSF, VSB) are connected to the front space or the back space at the first wall (112_1), and are disposed between the first wall (112_1) and the front supporting element; wherein a second front valve and a second back valve of the plurality of valves (VFF, VFB, VSF, VSB) are connected to the front space or the back space at the second wall (112_2), and are disposed between the second wall (112_2) and the back supporting element; wherein the plurality of actuators (122, 1522) are mounted on the plurality of membrane units, such that the plurality of membrane units flexibly perform the horizontal deformation. a front faceplate; a back faceplate; a front supporting element, connected to the front faceplate; a back supporting element, connected to the back faceplate; a folded membrane (110, 1510, 1610), configured to form a front chamber and a back chamber, and comprising a plurality of membrane units; wherein the plurality of membrane units are parallel and sequentially connected and an end of the folded membrane (110, 1510, 1610) is connected to the back faceplate via the back supporting element and another end of the folded membrane (110, 1510, 1610) is connected to the front faceplate via the front supporting element; a first wall (112_1), disposed along a first plane (P_1) corresponding to a side of the front supporting element with a first air flow channel (C_1) a second wall (112_2), disposed along a second plane (P_2) corresponding to a side of the back supporting element with a second air flow channel (C_2); and a plurality of valves (VFF, VFB, VSF, VSB) controlling the first and second air flow channels (C_1, C_2) between the front chamber toward either a front space or a back space, and between the back chamber toward either the front space or the back space; a plurality of actuators (122, 1522), each formed on a side of a membrane unit of the plurality of membrane units; wherein the plurality of membrane units are configured to perform horizontal deformation to squeeze air in and out of the front or back chamber with operations of the plurality of valves (VFF, VFB, VSF, VSB) controlling the direction of the air pulse toward the front space or the back space; wherein a first front valve and a first back valve of the plurality of valves (VFF, VFB, VSF, VSB) are connected to the front space or the back space at the first wall (112_1), and are disposed between the first wall (112_1) and the front supporting element; wherein a second front valve and a second back valve of the plurality of valves (VFF, VFB, VSF, VSB) are connected to the front space or the back space at the second wall (112_2), and are disposed between the second wall (112_2) and the back supporting element; wherein the plurality of actuators (122, 1522) are mounted on the plurality of membrane units, such that the plurality of membrane units flexibly perform the horizontal deformation.