A package structure includes a first substrate and a first device disposed on the first substrate. The first device includes at least one anchor structure, a film structure anchored by the anchor structure and an actuator configured to control the film structure to form a first vent temporarily. The film structure partitions a space into a first volume to be connected to an ear canal and a second volume connected to an ambient of a wearable sound device. The ear canal and the ambient are connected via the first vent when the first vent is opened. The first vent is opened by controlling a first membrane portion and a second membrane portion of the film structure, such that a difference between a first displacement of the first membrane portion and a second displacement of the second membrane portion is larger than a thickness of the film structure.