A sound producing device, comprising: at least one air pulse generating element (100, 200, 300 or 400), each of the at least one air pulse generating element (100, 200, 300 or 400) comprising: a membrane; and a first air chamber, wherein a chamber pressure exists in the first air chamber; characterized in that, each of the at least one air pulse generating element (100, 200, 300 or 400) further comprises: at least one opening connected between the first air chamber and an ambient surrounding the sound producing device; wherein the membrane is actuated to change the chamber pressure of the first air chamber to generate a plurality of air pulses at a pulse rate, the plurality of air pulses are propagated through the at least one opening, the plurality of air pulses produce a non-zero offset in terms of sound pressure level, and the non-zero offset is a deviation from a pressure value of an ambient pressure outside the sound producing device; wherein the at least one opening comprises at least one through hole; wherein the through hole has a diameter or a width less than or equal to 5 times a boundary layer thickness of a boundary layer of the through hole; wherein the pulse rate is higher than a maximum human audible frequency. at least one air pulse generating element (100, 200, 300 or 400), each of the at least one air pulse generating element (100, 200, 300 or 400) comprising: a membrane; and a first air chamber, wherein a chamber pressure exists in the first air chamber; a membrane; and a first air chamber, wherein a chamber pressure exists in the first air chamber; characterized in that, each of the at least one air pulse generating element (100, 200, 300 or 400) further comprises: at least one opening connected between the first air chamber and an ambient surrounding the sound producing device; wherein the membrane is actuated to change the chamber pressure of the first air chamber to generate a plurality of air pulses at a pulse rate, the plurality of air pulses are propagated through the at least one opening, the plurality of air pulses produce a non-zero offset in terms of sound pressure level, and the non-zero offset is a deviation from a pressure value of an ambient pressure outside the sound producing device; wherein the at least one opening comprises at least one through hole; wherein the through hole has a diameter or a width less than or equal to 5 times a boundary layer thickness of a boundary layer of the through hole; wherein the pulse rate is higher than a maximum human audible frequency. at least one opening connected between the first air chamber and an ambient surrounding the sound producing device; wherein the membrane is actuated to change the chamber pressure of the first air chamber to generate a plurality of air pulses at a pulse rate, the plurality of air pulses are propagated through the at least one opening, the plurality of air pulses produce a non-zero offset in terms of sound pressure level, and the non-zero offset is a deviation from a pressure value of an ambient pressure outside the sound producing device; wherein the at least one opening comprises at least one through hole; wherein the through hole has a diameter or a width less than or equal to 5 times a boundary layer thickness of a boundary layer of the through hole; wherein the pulse rate is higher than a maximum human audible frequency.