Abstract: A modular multiple microphone array method and mounting system that facilitates surround sound multichannel recording. Array configuration allows accurate and repeatable configurations suited to studio and field use. The lightweight design ensures portability and ease of placement in a variety of field recording situations: musical performance recording, film and video production, broadcast, sound effects recording, soundscape recording, etc. Versatility built into the array design allows compatibility with a variety of sound recording standards, from single channel mono to multichannel stereo and surround sound.

Abstract: A microphone housing to be mounted in a vehicle and having an electroacoustic transducer of a microphone arranged in the microphone housing has at least one sound entry opening, wherein the microphone housing when mounted projects past a surrounding surface of a component of the vehicle in which the microphone housing is mounted. The at least one sound entry, in the mounted state of the microphone housing, is positioned closely above the surrounding surface.

Abstract: The present invention relates to a directional microphone, in particular having symmetrical directivity, having an interference tube with a tube axis which is provided with a row of sound inlets arranged at least approximately parallel to tube axis, and which incorporates an electroacoustic transducer in its inside in the vicinity of its rear end face. It is further provided that the row of sound inlets is arranged non-symmetrically to tube axis opposite the outer periphery of interference tube.

Abstract: A catalytic converter for a small engine and a method for manufacturing the same include a honeycomb body coated with catalytically active material and made from at least partly structured layers of sheet metal with channels for the passage of exhaust gas. In order to reduce manufacturing costs, the honeycomb body is placed in a silencer housing disposed in the proximity of the engine, in such a way that at least a predominant portion of exhaust gas of the small engine has to flow through the honeycomb body. The honeycomb body is a layered, wound or folded stack of sheet metal layers, which is squeezed into the silencer housing, plastically deforming at least 10% and preferably 20 to 30% of the channels, so that it completely fills at least a partial volume of the housing.

Abstract: A device is provided for reducing noise in the human ear having a microphone which picks up the noise and a reproduction transducer to which a noise compensation signal is fed via a compensation circuit which is connected with the microphone. The microphone in the device has a balancing element which is arranged in front of the sound entrance opening of the microphone. The balancing element defines a quasi-constant sound reflection and accordingly reduces individual reflection effects caused by the fundamental diversity of the external region of the human ear and improves the use of the entire device and increases the effectiveness of the noise compensation overall. In this way, headphones/hearing protectors can also be designed as acoustically closed systems which are designed so as to rest on the ear.

Abstract: A honeycomb body that including wound sheet-metal layers including structured sheet-metal layers with structuring. The wound sheet-metal layers form an upper side, a lower side disposed remote from the upper side, a first edge region and a second edge region laterally extending from the upper side to the lower side. The second edge region is disposed remote from the first edge region. The wound sheet-metal layers are fixed in a common fixing zone at the first edge region. The structuring of the structured sheet-metal layers is at least partially flattened at the fixing zone so that adjacent wound sheet-metal layers lie close against each other at the common fixing zone. The wound sheet-metal layers preferably form a region with a flattened cross-sectional area. A muffler of an exhaust gas system of an internal combustion engine that includes the honeycomb body is also provided. In addition, a two-region housing that includes the honeycomb body is provided.

Abstract: A microphone includes a voice coil, a membrane and a diaphragm that has an annular convex portion encircling a central convex portion and a concentric cutout portion on the central convex portion. The membrane covers the cutout portion and extends to the periphery of the central convex portion. The combination of a properly designed cutout portion, the thickness of the membrane, the materials used for the membrane and the diaphragm, and the adhesive method employed to connect the membrane and the diaphragm shall result in a microphone that is capable of delivering high quality sound.

Abstract: A contact type indirect conduction, vibrating type microphone comprised of a body having a vibration damper on the inside, a fastening device connected to the body for fastening around the neck or the head, the vibration damper having a top recess, a peripheral flange, and a plurality of projecting rods raised from a bottom thereof, a capacitive microphone disposed within the top recess of the vibration damper, a sponge covered on the vibration damper over, and a top cover with a diaphragm covered over the sponge and adhered thereto by a double-sided adhesive tape.

Abstract: A windscreen for a remote microphone for mobile radios is disclosed. The sound absorbent material is held in place on the exterior surface of the microphone housing by means which permit easy detachment from the housing, thereby permitting replacement as the sound absorbent material deteriorates with age and exposure to the elements.

Abstract: A noise cancelling microphone for use in noisy environments is disclosed wherein noise entering the front portion of the microphone housing to impinge upon the microphone cartridge diaphragm is also permitted to enter proximate the rear portion of the microphone housing through strategically located inlet openings. This allows noise to impinge upon the back surface of the microphone cartridge diaphragm to effect a cancellation of diaphragm vibrations. These strategically located inlet openings at the top and the bottom of the rear of the microphone housing are situated so as to be directionally orientated towards the greatest source of the noise, namely orthagonal to the directional line of the front inlet openings and out of the path of the incoming air.

Abstract: A wind noise and vibration noise reducing microphone arrangement is formed in a bullet-shaped housing (12) having a rounded front portion (13) and a flat rear portion (15). The rear portion is substantially perpendicular to the side portions (14) and contains a transducer (10) facing in the opposite direction from the forward portion. The transducer is mounted to the housing with an elastomeric member (25) that also serves as a seal between the transducer and the housing. The elastomeric member also reduces vibrations transmitted to the microphone. A mounting means (30) is attached to the housing. The mounting means has a vibration isolation member (32) to reduce vibrations transmitted to the housing. The mounting means can be an aerodynamic pedestal attached to the housing, with an elastomeric member attached to the pedestal to reduce vibrations.

Abstract: A microphone, preferably of the type to be held in the hand or to be attached to a stand, includes a handle part, an intermediate part and a head part. At least the handle part is formed of two halves, each of which is symmetrical about a plane extending through the longitudinal axis of the handle part.

Abstract: This is a highly directional floor microphone. A pair of hinged panels rest upon the floor. A compliance may be used to acoustically seal the panels to the floor. At the apex of the floor and hinge is a transducer. The hinged panels are trapezoidal in shape and the hinge is acoustically opaque. The floor increases the directivity 6 dB. The panels increase the directivity by 12 dB. Tapering the panels in a trapezoidal shape increases the directivity by 2 dB. The total increase in directivity is 20 dB, allowing a working distance of ten times that of an omni-directional microphone. The folding nature allows easy storage and carriage.

Abstract: An electro-acoustic transducer includes a housing enclosing an electro-acoustic transducer device and having an opening by which the diaphragm side of the transducer device is exposed to the outside, and a ring provided to the outer surface of the perimeter of the opening. The outer perimeter of the ring is adapted to be softer and more pliable than the housing.

Abstract: A low puff boom microphone includes a protective grid covering an end portion of the microphone housing, a microphone capsule near the protective grid, a layer of material between the protective grid and microphone capsule, a spacer between the layer of material, and an open area laterally of the spacer.

Abstract: A microphone baffle apparatus having a baffle member having first and second sides with the first side shaped to form a sound baffling surface to absorb sound energy. The baffle member has an opening therethrough in the center portion thereof and has an elastic material attached around the opening so that a microphone can be slipped through the opening and the baffle member held to the microphone by the elastic material around the opening. The baffle member may be made of a plurality of sectors connected with ductile hinges to allow the baffle member to be bent into a plurality of shapes. In addition, each baffle sector may be made of a plurality of laminated layers of ductile material and bent to a variety of desired shapes. One layer may be a thin layer of lead and one side of the baffle may have a waffle shaped surface thereon.

Abstract: The microphone windscreen has a smooth level outer surface with decreased wind resistance and enhanced acoustic properties. The screen includes a resilient, hollow tubular body member of metal or plastic or the like, preferably polyethylene plastic, having a central space to hold a microphone and open front and rear ends. The sidewall of the member has a plurality of spaced openings to form a mesh configuration. A similarly constructed pair of hemispherical hollow end caps are welded or molded directly to the body by a weld or mold line to form the windscreen into a strong unitary porous cage structure, having decreased weight in comparison to conventional windscreens, and with reduced sound obstruction. The weld line is part of the smooth level outer surface of the windscreen. The inner surface of the windscreen is preferably covered by a wind noise attenuation medium such as a fabric formed of an outer layer of napped nylon, an intermediate layer of polymeric plastic foam and an inner layer of woven nylon.

Abstract: A construction for housing a microphone is disclosed. The construction is configured to improve the wind and noise protection for a small diameter microphone by providing a large diameter opening tapering to a smaller microphone aperture. The construction comprises a housing for a microphone transducer, and an adapter mateable with the transducer and housing. The adapter includes a plate having a greater diameter than the microphone aperture, and tapering to the smaller microphone diameter opening. In the preferred embodiments of the construction, a windscreen is included covering the tapered portion of the adapter.

Abstract: A pressure gradient pickup, particularly a capacitor microphone or a dynamic microphone, has a diaphragm arranged in a housing and at least one sound entry opening which conducts the sound to the rear side of the diaphragm. Acoustically acting phase-shifting sections are connected in the interior of the housing to the at least one sound entry opening. The at least one sound entry opening is located at least approximately in the same plane as the diaphragm and is preferably arranged concentrically relative to the diaphragm edge.

Abstract: A high frequency emphasis microphone particularly adapted to a hearing aid application provides a steeply rising frequency response characteristic relative to frequency, and has a low pass sonic attenuator for providing to the undriven side of the microphone diaphragm a sonic counterpressure which at low frequencies substantially cancels ambient sound pressure delivered to the driven side of the diaphragm, the attenuator reducing this counterpressure at elevated frequencies to provide accentuated high frequency response. The attenuator includes a pair of inertance-forming restricted passageways passing a portion of incoming sound to a bypass port leading to the undriven side of the diaphragm, the passageways being defined by a U-shaped plate disposed within a chamber confronting the driven side of the diaphragm.

Abstract: A stepped frequency microphone particularly adapted to a hearing aid application provides a stepped frequency response characteristic relative to frequency, and has a low-pass sonic attenuator for providing to the undriven side of the microphone diaphragm a sonic counterpressure which at low frequencies substantially cancels ambient sound pressure delivered to the drive side of the diaphragm, the attenuator reducing this counterpressure at elevated frequencies to provide accentuated high frequency response.

Abstract: A narrow directional microphone comprising a microphone unit having forward and rearward sound terminals, and an interference pipe to cooperate with said microphone unit and to effect a narrow directional orientation. The microphone unit is positioned at its outer periphery to take a position at a distance to an inner periphery of the interference pipe in a rear end of the interference pipe. The interference pipe having a plurality of sound wave inlets at a distance in a circumferential direction at a portion taking position on said rearward sound terminal of said interference pipe.

Abstract: A diaphragm for use as a pressure receiving and dislocatable member in a condenser-type microphone detector. The diaphragm electrode is a thin metallic film member having a central movable portion, a supporting frame portion around the outside of and spaced from the central movable portion, and at least three supporting spring portions at equal intervals around the periphery of the central movable portion and connected between the central movable portion and the supporting frame portion for permitting the central movable portion to be moved out of the plane of the supporting frame portion by differential pressure across the opposite sides of the central movable portion. The central movable portions can have holes therein for partly relieving the pressure thereon.

Abstract: A hollow enclosure that suspends a bidirectional microphone element within, in such a fashion as to improve the unidirectional characteristics, of said bidirectional microphone.

Abstract: A microphone system comprising a pair of microphone capsules, a pair of planar barriers positioned at an angle to each other, with each microphone capsule secured to the center portion of a barrier positioned between the microphone capsules. A baffle is positioned between the microphones with the sidewalls of the baffle extending angularly toward the barriers forming corners with each of the microphone capsules located at the corner.

Abstract: An electroacoustic device comprises an array of electroacoustic transducer elements for producing a prescribed directional response pattern at a first frequency. Each element includes apparatus for restricting the frequency range of sound waves incident on said element so that the directional response pattern is invariant over a prescribed frequency band.

Abstract: A condenser microphone utilizable at high temperature and intense radioactive rays. The microphone has a tension ring and a backplate, both of which are made of a metal having a small coefficient of linear expansion relative to the other parts of the microphone. The tension ring is fitted to a tension ring holder, and the backplate is mounted on the tension ring holder through an insulating material so that the tension ring and the backplate are held together to form a unitary structure.

Abstract: An acoustic equalizer adapted for use with a microphone includes a resonator plate having front and back faces, a lip surrounding the plate and defining a first air cavity in the back face of the plate, and a plurality of apertures formed through the thickness of the plate, which apertures communicate with the first cavity. A boss is formed centrally on the front face of the plate. The boss is closed ended on one side and hollow interiorly to define a second air cavity. The first and second cavities communicate with each other through a central opening formed in the plate.

Abstract: Acoustic frictional resistance comprises a plate having at least one laser-formed hole therethrough. The plate is formed by positioning a plate preferably one having a thickness smaller than one and one-half milimeters alongside a laser and directing the laser beam so that it cuts a hole through the plate. During the process of producing the resistance, the value of the acoustic friction is measured as a pressure drop of a constant air stream or as an expenditure of electrical energy for an electrically excited electroacoustic transducer. This measurement is then used as a variable or as a standard for controlling the process. Advantageously, a coherent beam is emitted by the laser which is deflected by mirror from a horizontal to a vertical direction and focused by means of a lens to work in a contact-free manner on a workpiece supported on a support member such as a movable table. By moving the table in two coordinate directions, a plurality of bores are formed in a pattern in a workpiece.

Abstract: A unidirectional microphone windscreen which includes portions formed of compressed foam and uncompressed foam located on opposite sides of the capsule to enhance directivity of the microphone.

Abstract: A flush-dish microphone system for measuring aircraft flyover noise is disclosed. The system includes an acoustically hard base supporting a microphone. The base is configured along its periphery to define a plurality of outwardly extending tapered members. Each of the tapered members includes a pair of converging edges that are each at least in part curved. The curved edges produce a favorable progressive match of acoustic impedance at the ground/tapered member boundary that reduces edge diffraction contamination of the noise signal being measured by the microphone.

Abstract: A moulded suspension for an electro-acoustic transducer in the form of a microphone or a receiver has three regions. A transducer supporting region fits closely around the transducer. A tubular inlet region connects the acoustical inlet or outlet of the transducer to a respective port of the appliance containing the transducer. The third region is a tubular foot which has an annular flange so that the moulding can be mounted adjacent to an aperture formed in a supporting plate. The suspension is made of an elastomeric material. It provides a high degree of vibration isolation and is particularly suitable for use in "behind-the-ear" hearing aids.

Abstract: A microphone wind shroud having a integral mounting means for being slidably mounted to an omnidirectional or unidirectional microphone, such as those integrally mounted on video cameras. A semi-rigid grid-like external shell shrouds the microphone head. The shell is lined with a multilayer laminate fabric material. The shell and laminate allow desired audio frequencies to pass and reach the microphone head while attenuating undesired wind noises caused by microphone movement or environmental wind conditions.

Abstract: A directional acoustic transducer includes a plurality of acoustic paths each having first and second ends. The second end of each path terminates in the atmosphere. An electroacoustic device is attached to an acoustic cavity and the acoustic path first ends are coupled to the said acoustic cavity through an acoustic arrangement adapted to produce a predetermined transducer directional response pattern.

Abstract: A diaphragm for electrostatic and electrodynamic microphones which has a distinct directional pattern comprises a taut diaphragm having a thickness of less than 8 microns and a diameter of 10 millimeters at most and which is made of an elastically extensible rubber base material which has a natural frequency of 1,200 Hz to 1,500 Hz at most. A diaphragm is particularly for microphones of the cardioid, supercardioid and hypercardioid and figure eight type.

Abstract: A microphone for stethoscopes and the like having a weighted head member with a recessed cavity formed therein. A diaphragm is sealed to the head member with an adhesive material to provide an airtight cover for the cavity. The mass of the head member causes it to remain substantially vibration free and as a result all vibrations are transmitted directly to the diaphragm causing it to vibrate with increased amplitude at all frequencies. The adhesive seal between the diaphragm and the head member effectively eliminates secondary vibration thereof so that the microphone is capable of producing a distortion free air signal of high amplitude at all normal frequencies.

Abstract: A microphone, particularly for hearing aid application, said microphone providing a stepped response characteristic relative to frequency wherein low frequency sounds will couple to the associated hearing aid with a restricted amount of amplification, while providing an emphasis or higher amplification for the higher frequencies in the bandwidth of interest.

Abstract: An electroacoustic two-way transducer assembly particularly for headphones and microphones comprises an electrostatic treble system having an electrostatic treble system disphragm and an electrodynamic system disposed under said electrostatic treble system. The electrodynamic system has an attachment portion with a flat front side forming a disc-shaped back plate for the electrostatic treble system diaphragm.

Abstract: A microphone unit particularly suitable for conference applications is provided, wherein an acousto-electric transducer is disposed between two dish-like back-to-back sound collectors, each having a central aperture exposing one side of the transducer, which preferably has a single planar diaphragm.

Abstract: A unidirectional dynamic microphone provided with a first sound path to the forward side of the diaphragm and a second sound path to the rear side of the diaphragm in which the second sound path has a chamber coupled to a second chamber associated with the diaphragm through a distributed acoustic RC damping assembly.

Abstract: A unidirectional dynamic microphone provided with a first sound path to the forward side of the diaphragm and a second sound path to the rear side of the diaphragm, a Helmholtz resonator disposed in the first sound path having a sound entrance, and a diffraction lens mounted ahead of the Helmholtz resonator and partially shadowing the sound entrance to the Helmholtz resonator for the purpose of increasing the high frequency response of the microphone.

Abstract: A method and a device for picking up sounds from a piano by a microphone placed between a wall of a piano case in opposed relation with a sounding board and a surface located in opposed relation with the sounding board of a sound-absorbing member. The sound-absorbing member consists of a planar body or a hollow body having an anechoic enclosure with bidirectivity and with both open ends cut away at angles relative to the axis of the enclosure, and the microphone is placed between the planar body and the wall or in the anechoic enclosure.

Abstract: A disposable noise reducing hearing attachment provided for covering the sound inlet of a hearing aid to reduce the amplitude of random noises such as wind noises and to prevent dirt and moisture from entering the sound inlet. The attachment includes a flexible open cellular noise filter that is covered by a thin sheet of tightly woven material to form a wind and dust screen on the top surface of the noise filter. A stretchable bottom ring layer of nonporous sheet material is attached to the bottom surface of the noise filter in which the bottom ring layer has an aperture that is greater than the cross section of the sound inlet. The top wind screen layer and the bottom ring layer are secured to opposite sides of the noise filter layer by rings of adhesive that have diameters greater than the cross-sectional diameter of the sound inlet of the hearing aid so that adhesive does not interfere with the sound transmission through the attachment and into the hearing aid through the sound inlet.

Abstract: A loud speaker having air communicating holes within the rear portion of the frame and facing the diaphragm is provided with regularly woven wire gauze formed of warp and weft wire threads of different diameter, which gauze covers the communicating holes to obtain a stable vibration damping effect.

Abstract: A pressure gradient directional microphone of the moving coil type in which the acousto-mechanical function of the transducer is achieved by a vibratile diaphragm the major area of which is of coneiform shape and the central portion of which is of dome shape and of significantly smaller area and provides a surround for attaching the coil. One side of the diaphragm is exposed to the sound field surrounding the microphone, and the other side is exposed to two cavities, one of relatively large volume behind that portion of the diaphragm which is of coneiform shape, and a second behind the dome portion which is sufficiently smaller that it is unnecessary to provide any phase-shift action for any sound pressure generated therein. The diaphragm is secured at its periphery to a support ring having a plurality of openings formed therein which serve as acoustic ducts from the ambient into the larger cavity.

Abstract: A damping element comprising fiberous fuseable material shaped to form a cup-like member which may be inserted in the sound openings of an acoustic transducer to provide a selected acoustic resistance.