Abstract: A microphone includes a microphone unit configured to convert a sound wave into an electrical signal. A cylindrical housing accommodates the microphone unit, and includes a a first opening portion that transmits the sound wave to the microphone unit. A sheet member having an air-permeable property and a water-repellent property covers the first opening portion. A frame including a second opening portion having a shape corresponding to a shape of the first opening portion covers the sheet member at a position of the first opening portion. A wind screen having a drainage property covers an exterior of the housing.

Abstract: To provide an impedance converter circuit for a condenser microphone which can secure a wide dynamic range using a voltage amplifier circuit. The impedance converter circuit is provided with: a first electron tube of a cathode grounded type in which an output signal of a condenser microphone unit is input into a grid and output from a plate; a second electron tube in which an output signal from the plate of the first electron tube is input into a grid and output from at least a cathode; and a feedback element configured to transmit a feedback signal from the cathode of the second electron tube to the grid of the first electron tube.

Abstract: A microphone includes a microphone unit having a diaphragm vibrating in response to sound. The microphone unit converts the sound into an electrical signal. A cylindrical casing contains the microphone unit. A metal mesh strip rounded along the inner surface of the casing is attached to the inner surface of the main wall of the casing so as to cover openings. The rounded metal mesh strip has a spring portion generating spring force to expand the metal mesh strip against the inner surface of the casing to provide electrostatic shielding.

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: A unidirectional condenser microphone includes a diaphragm, a fixed electrode disposed opposite a back face of the diaphragm and an electrode extraction part for the fixed electrode disposed at a backside of the fixed electrode and having a through hole adapted to capture a sound wave from a rear acoustic terminal into a backside of the diaphragm. The through hole has a horn-shaped opening formed in continuation of the through hole at the rear acoustic terminal side thereof such that an inner diameter of the horn-shaped opening is increased toward the rear acoustic terminal side. The electrode extraction part has a plurality of the through holes formed therein at regular intervals along a concentric circle around an axial center of the electrode extraction part, and all the through holes along the concentric circle have the horn-shaped openings formed therein, respectively.

Abstract: A noise-cancelling headphone is provided that avoids an influence of the wind and prevents degradation in the sound quality of the reproduced sound output from a driver unit. The noise-cancelling headphone includes an ear piece including a housing unit having an interior and an exterior, a driver unit attached to the housing unit, and a microphone collecting external sounds at the exterior of the housing unit. The housing unit includes an accommodating portion accommodating the microphone and a sound collecting hole establishing the communication between the accommodating portion and the exterior of the housing unit. The accommodating portion is disposed in an upper portion of the housing unit of the noise-cancelling headphone when worn by the user. The sound collecting hole is open toward the upper side of the housing unit of the noise-cancelling headphone when worn by the user.

Abstract: A microphone includes: first and second bi-directional microphone units having respective directional axes arranged on two straight lines passing through one point and radially extending with an interval of 120 degrees; a third bi-directional microphone unit having a directional axis arranged on a straight line perpendicular to a plane formed by the two straight lines; and an omnidirectional microphone unit arranged in sound collection regions of the first, second, and third bi-directional microphone units.

Abstract: A microphone apparatus includes a microphone including first and second bi-directional microphone units having respective directional axes arranged on two straight lines passing through one point and radially extending with an interval of 120 degrees in a circumferential direction, and an omnidirectional microphone unit arranged in sound collection regions of the first and second bi-directional microphone units, and a signal synthesis unit that synthesizes at least one of respective non-inverted signals and inverted signals of the first and second bi-directional microphone units and an output signal of the omnidirectional microphone unit to generate a plurality of output signals having directional axes in mutually different directions.

Abstract: A microphone holder includes: a holding member holding a microphone; and a mounting member fixed to a tension bolt for fixing a rim of a drum. The mounting member includes a first clamping portion having a first locking portion locking to a lower surface of the rim, a second clamping portion having a second locking portion locking the tension bolt, and a biasing member biasing in a direction allowing the first clamping portion and the second clamping portion to approach, wherein the mounting member is attached to the tension bolt by clamping the rim and the tension bolt between the first clamping portion and the second clamping portion, in a state that the first locking portion of the first clamping portion is locked to the lower surface of the rim and the second locking portion of the second clamping portion is locked to the head of the tension bolt.

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 microphone device includes an audio signal output circuit that balanced-outputs, through a balanced transmission line, an audio signal output from a condenser microphone unit, a balanced output terminal including a hot terminal, a cold terminal, and a ground terminal connected to the balanced transmission line, a power supply circuit that supplies a phantom power supply to the audio output circuit from the balanced output terminal through the balanced transmission line, and a display circuit including light emitting elements that perform lighting and non-lighting according to an operation of a manual switch, and the display circuit includes constant current elements that generate a constant current through the balanced transmission line, a constant voltage element connected to the constant current elements and which generates a constant voltage, and light emitting elements connected to the constant current elements, and to which the constant voltage by the constant voltage element is applied.

Abstract: A unidirectional condenser microphone having a front opening portion and a rear opening portion for respectively passing sound waves to a front surface and a back surface of a diaphragm of a microphone unit, the unidirectional condenser microphone includes: an acoustic tube provided in the front opening portion; a first air chamber provided between the rear opening portion and the back surface of the diaphragm of the microphone unit, and having a predetermined acoustic capacity; and a second air chamber communicating into the first air chamber, and having an acoustic capacity larger than the predetermined acoustic capacity, wherein sensitivity to a direction of 0° with respect to a directional axis is improved by the first air chamber and the acoustic tube, and a proximity effect due to the sound wave from a direction of 180° with respect to the directional axis is prevented by the second air chamber.

Abstract: A non-directional microphone includes a housing, a microphone unit attached to the housing, and including a diaphragm that receives a sound wave, and a connector portion to which a cable connector including a cable that transmits an audio signal from the microphone unit is connected, and a pressure equalization opening that allows a back-side space of the diaphragm in the housing and an outer space to communicate is provided in the connector portion. In the non-directional microphone, the communication between the back-side space of the diaphragm and the outer space through the pressure equalization opening is cut off when the cable connector is connected to the connector portion, and the back-side space of the diaphragm communicates into the outer space through the pressure equalization opening when the cable connector is disconnected from the connector portion.

Abstract: Provided is a condenser microphone having a plurality of condenser microphone units connected in series to improve output sensitivity, and a simplified circuit configuration. At least one of the preceding condenser microphone units, excepting a last condenser microphone unit, and an adjacent succeeding condenser microphone unit are directly connected to transmit an audio signal obtained from the at least one of the preceding condenser microphone units to the adjacent succeeding condenser microphone unit. An impedance converter using an active element is connected to the last condenser microphone unit, and the audio signals obtained from the condenser microphone units are added and output from the impedance converter using the active element.

Abstract: An electrode extraction terminal extracting a generated current by contacting with a fixed electrode is disposed inside a unit case, and can change from a cardioid to a hyper cardioid. The electrode extraction terminal includes an electrode rod portion having a projection portion at a tip side; and a pedestal portion having a flat surface surrounded by a peripheral wall portion having a sitting height thereof same as that of the projection portion of the electrode rod portion, and facing the fixed electrode under a shape with a size showing a cardioid in directivity, wherein the flat surface is located orthogonal to an axis direction of the electrode rod portion. In a peripheral surface area of one or more sound holes of the flat surface, a minute concave-convex surface is provided to reduce an acoustic resistance value to show a hyper cardioid in directivity.

Abstract: A microphone includes a tubular first and second acoustic tubes configured with a gap between the second acoustic tube and an inner side of the wall surface of the first acoustic tube. A first opening portion is provided in a wall surface of the first acoustic tube. A second opening portion is provided in a wall surface of the second acoustic tube. A microphone unit is provided inside the second acoustic tube and is configured to acquire sound waves from outside the microphone. A sound wave introduction path formed by the first opening portion, the gap, and the second opening portion, is configured to transmit the sound wave from the outside to the microphone unit.

Abstract: An ear pad to be mounted to a base body to which a speaker unit is fixed includes an elastic body in which a plurality of elastic members having different coefficients of restitution are laminated together in a sound emitting direction of the speaker unit. A skin material covers an exterior of the elastic body. The elastic body includes a first elastic member arranged at a side of the base body, and a second elastic member laminated on and fixed to the first elastic member. The first and second elastic members respectively have ring shapes having a substantially same external diameter. The second elastic member has an inner peripheral surface having a different dimension compared to an inner peripheral surface of the first elastic member, and has a portion having a larger inner diameter than an inner diameter of the first elastic member.

Abstract: A diaphragm is provided that has small mechanical anisotropy even when heat is applied to the diaphragm in the production process. The diaphragm includes a biaxially stretched film stretched in a first direction (the machine direction) and a second direction (the transverse direction), wherein the entire surface of the biaxially stretched film has a first pattern and a second pattern, the first pattern has ridges and grooves with a first pitch, the second pattern has ridges and grooves with a second pitch, the second pitch is smaller than the first pitch, the second pattern is formed along the first direction or the second direction, and the length of regions defined by the first pattern in the first direction differs from the length of the regions in the second direction.

Abstract: A digital microphone includes: a cavity resonator operatable in a micrometer, millimeter, or electromagnetic waveband, the cavity resonator having a metal wall including a conductive membrane 32 that vibrates in response to incident acoustic waves and converts the shift of the membrane 32 into a resonance frequency of the cavity resonator; an FM-signal generator that modulates the resonance frequency of the cavity resonator in response to the shift of the membrane 32 and outputs FM signals from the metal wall other than the membrane; and a ??-modulated-signal generator that generates ??-modulated signals from the FM signals. The FM-signal generator includes a slot 36, a micro-strip line 38, and a negative resistive element 40. The ??-modulated-signal generator includes an edge detector 42.

Abstract: A handheld microphone includes a microphone unit supported with a vibration insulator on a microphone case; the handheld microphone comprising a filter circuit for filtering output signals from the microphone unit; the filter circuit comprising a passive filter connected to an output terminal of the microphone unit, and a high-pass filter connected downstream of the passive filter and outputting the filtered signals from the microphone unit.