Abstract: A sensing device including a sensitive part and a first sensor. The sensitive part includes a sealed internal space. At least part of the sensitive part is flexible and configured to be flexed, by a load applied on the sensitive part or by vibration of the sensitive part, so as to change an air pressure in the internal space. The first sensor borders the internal space or is at least partly housed in the internal space. The first sensor includes at least one sensing part configured to detect changes in the air pressure in the internal space.

Abstract: The fluid sensing device including a sensitive part, at least one obstacle, and a sensor. The sensitive part includes a flexible portion extending in a second direction substantially orthogonal to a first direction or fluid flow direction. The at least one obstacle extends in the second direction and is located in spaced relation to, and upstream of, the flexible portion. A collision of the fluid with the at least one obstacle generates vortexes in the fluid alternately on opposite sides in a third direction relative to the at least one obstacle, so that one or more of the vortexes collide with the flexible portion so as to distort at least part of the flexible portion. The third direction is substantially orthogonal to the first and second directions. The sensor includes at least one sensing part to detect the distortion of the flexible portion as a flow of the fluid.

Abstract: A condenser-type sounding body unit is provided with a casing; a plate electrode comprising a conductor; a diaphragm disposed in opposition to the plate electrode; a spacer for insulating the plate electrode and the diaphragm, the spacer being disposed between the plate electrode and the diaphragm; a pair of signal input terminals electrically connected to the plate electrode and the diaphragm respectively; and a sandwiching section. The sandwiching section has a first sandwiching section comprising an insulating material and a second sandwiching section comprising a conductive material. The sandwiching section sandwiches the plate electrode and the diaphragm from both sides in the direction of opposition thereof. The diaphragm, in a state of being affixed to the second sandwiching section, is housed within the casing. A sound hole is formed in the casing, in a position in opposition to the diaphragm.