Abstract: An electro-acoustic transducer includes a needle electrode, an opposite electrode, a discharge region between the needle electrode and the opposite electrode, a high-frequency oscillating circuit in the discharge region causing a high-frequency discharge and modulating and extracting an audio signal in accordance with a sound wave introduced to the discharge region, or converting the discharge in the discharge region into a sound wave, the discharge being performed in accordance with a high-frequency signal modulated by an audio signal, and an inert gas supply channel that supplies inert gas toward the peripheral surface of the needle electrode. The electro-acoustic transducer includes a needle-electrode cover as a part of the inert gas supply channel. The needle-electrode cover extends beyond the tip of the needle electrode toward the opposite electrode and has a gas flow outlet disposed beyond the tip of the needle electrode toward the opposite electrode.

Abstract: A handset microphone includes: a microphone unit, a first switch for turning on or off the output from the microphone unit, and a second switch for enabling or disabling the output from the microphone unit; the first and second switches have contacts operated by a magnetic field; the contact of the first switch is closed and short-circuits the output terminals while the first switch is being affected by the magnetic field; and the contact of the second switch is opened and disconnects one of the output terminals while the second switch is being affected by the magnetic field.

Abstract: A handheld condenser microphone is provided with a condenser microphone unit having two unidirectional condenser elements. A conductive fabric 221 is put between a lock ring 213 and the second condenser element 10b, when an acoustic-electric transducer 220 is fixed inside a unit case 210 by fastening force of the lock ring 213.

Abstract: A connector according to the invention includes: a metal cylinder; a conductive receptacle having an end fitted in an end of the metal cylinder; a pin assembly fitted in the conductive receptacle; pins fixed to the pin assembly, the pins being connected to a cable; a circuit board fixed to the other end of the metal cylinder, the circuit board having through holes electrically connected to the pins; and a sealant disposed between the circuit board and the pin assembly, the sealant infilling gaps between the pins and the through holes of the circuit board.

Abstract: A microphone includes a volume reduction filling member therein. The volume reduction filling member includes an elastic body having an insertion hole for inserting an electrode extraction member which extracts a generated current to a back end side by contacting a front end side thereof to a fixed electrode of a microphone unit, and reducing a volume inside a unit case. The elastic body is divided into a tip-side main body portion and a base-end-side flexible flange portion through a circular groove around the insertion hole from an outer peripheral face side of a base end portion thereof. When an outer peripheral edge portion of the base-end-side flexible flange portion receives an equal pressure toward a tip direction so as to bend, the elastic body concentrates a stress into a front portion side of the insertion hole through the tip-side main body portion.

Abstract: A boundary microphone that can reduce the change in its directional property caused by change of a sound collection axis of a microphone unit is provided. The boundary microphone includes a unidirectional microphone unit, a cylindrical unit holding member having a unit accommodating pocket in its peripheral surface to accommodate the unidirectional microphone unit, and a boundary plate to which top face the unit holding member is attached so as to rotate about its axis. When the unidirectional microphone unit is held in the unit holding member, a front acoustic terminal is positioned to face the outside of the peripheral surface of the unit holding member, the sound collection axis intersects the axis of a hollow of the unit holding member, and a rear acoustic terminal communicates with the outside at both side ends of the hollow via the hollow of the unit holding member.

Abstract: The stereo boundary microphone includes a boundary plate, a case body attached to the boundary plate and having an elongate shape including left and right grooves provided in opposite sides and extending along the longitudinal direction, first and second side walls covering the grooves included in the case body by predetermined distances to form left and right acoustic passages, and first and second microphones contained in tail end portions of the acoustic passages so as directional axes of the first and second microphones to be parallel. An opening communicating with the tail end portion of the case body is provided and services as a rear acoustic terminal to be used by both the first and second microphones. Front ends of the acoustic passages formed by the side walls serve as left and right front acoustic terminals of the first and second microphones.

Abstract: The orientation of the directional axis and the directionality of a microphone are adjusted through a simple configuration.

Abstract: There is provided a microphone device with which an operation state of the microphone device may be easily checked and that may effectively reduce noise to be played back, the noise being caused by vibration that has propagated through a table or the like. A microphone device is configured such that a microphone case 2 in which a microphone unit 3 for converting a speech wave into a speech signal is housed is supported by a stand arm 25 via a coupling member 11 formed of a light-transmissive elastic material, and light emitted from a light source (LED) 14 housed in the microphone case 2 or the stand arm 25 is projected to an outside through the coupling member. Control is performed such that the light source 14 is lit in an on state in which a speech signal is output from the microphone unit 3.

Abstract: A variable directional microphone includes a unidirectional microphone unit having a front acoustic terminal and a rear acoustic terminal; an acoustic tube which accommodates the microphone unit therein and having a plurality of acoustic resistance openings in a circumferential wall thereof; a supporting member mounted within the acoustic tube to be movable along an axis of the acoustic tube and supporting the microphone unit, the supporting member having a predetermined acoustic resistance and allowing transmission of sound waves; and further includes a gap formed between an outer circumferential wall of the microphone unit and an inner circumferential wall of the acoustic tube for providing communication between the front acoustic terminal and the rear acoustic terminal. Directionality of the variable directional microphone changes depending on the position of the microphone unit in the acoustic tube.

Abstract: A boundary microphone includes a microphone and a boundary plate on which the microphone is placed. The boundary plate includes a porous metal material of an aluminum-based metallic fiber layer clamped by an aluminum-based expanded metal and crimped thereto. The boundary plate has a characteristic of absorbing an incoming sound wave without reflecting the sound wave to the microphone, and the microphone collects a direct sound.

Abstract: A dynamic microphone which prevents a wall forming a back-side air chamber from having a certain resonance frequency and effectively prevents the generation of standing waves in the back-side air chamber is provided. A dynamic microphone includes a dynamic microphone unit including a diaphragm configured with a voice coil and a magnetic circuit having a magnetic gap provided so as to allow the voice coil to vibrate, a bottomed case which is coupled to the dynamic microphone unit and forms a back-side air chamber communicating with back side of the diaphragm, and an acoustic resistance body which is pressingly attached in the case and composed of metal fiber including a pocket, an open cross sectional area of the pocket gradually decreasing toward the direction remote from the dynamic microphone unit.

Abstract: In a primary sound pressure-gradient type condenser microphone unit driving a diaphragm by difference in sound pressure applied to acoustic terminals in front and back of the diaphragm, a drive force of the diaphragm and sound collection characteristics in a high frequency band are easily adjusted. The condenser microphone unit includes a first pipe extending forward on the front side of a diaphragm and a second pipe arranged so as to surround the first pipe. A front acoustic terminal communicating with a front surface of the diaphragm is formed on an inner side of either one of the first pipe or the second pipe. A rear acoustic terminal communicating with a back surface of the diaphragm from the rear side of a fixed electrode is formed on an inner side of the other pipe.

Abstract: Provided is a dynamic headphone that has a small size but makes a larger-diameter headphone unit mountable thereon, the dynamic headphone including a highly reliable acoustic channel that acoustically connects a front air chamber and a back air chamber to each other. A headphone case 20 houses a headphone unit 50 therein, and includes a back air chamber C2 on a back side of the headphone unit 50. The headphone case 20 includes: a back air chamber forming portion 40 that forms the back air chamber C2; and a mount portion 30 integrally provided to an opening end of the back air chamber forming portion 40, the headphone unit 50 being mounted in the mount portion 30. An acoustic channel 70 is provided between the mount portion 30 and the headphone unit 50.

Abstract: A throat microphone includes a cantilevered piezoelectric device 1 having a fixed end 11 supported by a base 3 and a free end with an anchor 4 fixed thereto. The piezoelectric device 1 vibrates to output audio signals in response to vibrations of a throat. The fixed end is attached to the base 3 such that the piezoelectric device 1 vibrates parallel to the surface of the base 3. A gap is defined between the anchor 4 and the base 3. The gap is provided with a vibration absorber 5.

Abstract: A microphone 1 includes a circuit board 22 equipped with electronic circuits, a microphone unit 26, and a case 21 accommodating the circuit board 22 and the microphone unit 26. The case 21 is a resilient hollow cylinder. The circuit board 22 has a substantially rectangular shape and has shorter sides having a length substantially equal to the inner diameter of the case 21. The circuit board 22 includes contact adapters 222 in contact with the inner wall of the case 21, along the longer sides of the circuit board 22.

Abstract: Provided is a variable directivity electret condenser microphone that can simplify a circuit configuration, and outputs an audio signal in a balanced manner, which includes electrically independent first and second electret condenser microphone units in which first and second fixed electrodes are arranged back to back and facing each other in a mutually non-conductive state, and first and second diaphragms are arranged facing the first and second fixed electrodes with fixed intervals therefrom respectively, a first impedance converter having an input terminal connected to the first fixed electrode, and a first buffer circuit connected to the first impedance converter, a second impedance converter having an input terminal connected to the second fixed electrode, and a second buffer circuit selectively connected to the second impedance converter, and a directivity variable switch that can alternatively select a mode from at least a first directivity mode to a third directivity mode.

Abstract: In an electrodynamic electroacoustic transducer, a diaphragm assembly including a diaphragm and a voice coil is attached to a unit housing accurately and easily. A peripheral portion of the diaphragm curves upward while forming a downward convex portion toward an end portion side thereof. In an opening edge portion of the unit housing, a support base portion contacting the downward convex portion of the diaphragm is formed and a concave portion which a peripheral end portion of the diaphragm engages with is formed in an inside surface. In the diaphragm, the downward convex portion is supported by the support base portion of the unit housing in the peripheral portion thereof, so that the peripheral end portion engages with the concave portion of the unit housing in a state in which the peripheral end portion has upward elastic force.

Abstract: Provided is a variable directivity electret condenser microphone that can simplify a circuit configuration, and outputs an audio signal in an unbalanced manner. Included are electrically independent first and second electret condenser microphone units in which first and second fixed electrodes are arranged back to back and facing each other in a mutually non-conductive state, and first and second diaphragms are arranged facing the first and second fixed electrodes with fixed intervals from the first and second fixed electrodes, respectively, a first impedance converter having an input terminal connected to the first fixed electrode, a DC cut capacitor selectively connected between an output terminal of the first impedance converter and an input terminal of the second impedance converter, and a directivity variable switche that can alternatively select a mode from at least a first directivity mode to a third directivity mode.

Abstract: A connector of a microphone includes a cylindrical connector case 1 having openings at both ends and a projection 10 on an inner face thereof; two substrates 11 and 12 having shapes fittable to the inner face of the cylindrical connector case 1, the substrates 11 and 12 facing each other across the projection 10 in the cylindrical connector case 1; and a connector pin 2 extending through the substrates 11 and 12 in the cylindrical connector case 1, having a contact 21 that is electrically connected to electronic parts 16 mounted on the substrates 11 and 12, and having a caulked portion 23 fixed to one of the substrates 11 and 12 on an opposite side to the contact 21.