Abstract: An automatic tilt speaker has a first subassembly of a speaker unit enclosing an ordinary speaker element. The speaker unit includes a cone-shaped housing having an inner cavity for holding the speaker with its frame or basket fitted snugly in an annular frame. The housing of the speaker unit is pivotally connected to the frame by a pivot arm. The speaker housing has an arcuate exterior wall extending in a radius centered about the pivot connection of the frame. Centrally of the arcuate wall, there is a gear arch, which comprises a vertical column of horizontally elongated teeth extending substantially coplanar with the arcuate wall. On the annular frame at the diametrically opposite side of the pivot connection a tilting system is operatively connected with the teeth. The tilting system includes a motor with a reduction gearbox for driving a worm gear, which in turn drives the gear arch. The annular frame also supports a relay-based motor control board for controlling the polarity and power to the motor.

Abstract: There is provided a headphone with a behind-the-head headband comprising at least one transducer and a behind-the-head headband for receiving the transducer. The behind-the-head headband further comprises first and second contact locations for resting against a temporal bone of a wearer of the headphone. The spacing between the transducer and the first or second contact location can be adjusted. By virtue of the possibility of adjusting the spacing with respect to the contact location the transducer can be positioned exactly over the auditory channel of the headphone wearer without pressure points on the ear.

Abstract: A portable system includes a hostable USB controller, USB decoder and speakers. The system operates to play audio files from external devices when powered.

Abstract: A convenient electronic sound producing device is an electronic sound producing device that is physically configured to be easy to use in the field. A control module faces the use while the sound is projected away from the user. A pistol grip can be used to ease holding and using the call. A remote can further ease operation and allow control from a distance. A timer allows for nearly autonomous operation. Control modules can be fixed to a firearm, bow, crossbow, or camera to minimize the user's movement while simultaneously calling and preparing for a shot. A pinning hole or a stake can allow for reliably fixing the sound producing device to a surface, to vegetation, or to other objects.

Abstract: The invention discloses a flush type rotatable sound box comprising a body case and the loudspeaker system inside the case. The mentioned body case is flush-mounted in wall or ceiling with a revolving gear joining to them. The sound box of this invention saves space and beautifies the indoor environment. The angle of the sound box can be changed depending on user's listening habit and the requirements of sound field by controlling the revolving gear. When the sound box is not to be used, it can be rotated by 180° with the revolving gear in order to keep it in wall or suspended ceiling and to reveal its back. A lighting devices or decoration may be fixed to the back of the sound box upon user's request.

Abstract: An audio visual system has a housing with a video display and one or more speakers. The speakers are housed in cavities which limit dispersion of the sound generated, and the video display is preferably a directional LCD display. The housing is preferably mounted to a base by an adjustable arm having passages to accommodate enclosed wiring. One adjustable arm has segments joined by dual-pivot joints, while another has segments joined by single pivot joints. In both types of arms, the frictional resistance of the joints can be adjusted. Preferably, the elements of the arm are strung onto the wiring prior to assembly. The housing can also contain a light source to provide a reading light.

Abstract: A speaker assembly aimable relative to a remote target. The speaker assembly comprising a sound generating device configured to project sound in a sound pattern about a sound axis. A speaker aiming device is coupled to the sound generating device for use in visually aiming the sound generating device relative to the remote target. The speaker aiming device having first and second aiming portions spaced apart from each other and positioned along an aiming axis in a fixed orientation relative to the sound axis. The first and second aiming portions being positioned to allow a user to visually see along the aiming axis past the first and second portions aiming device to the remote target.

Abstract: A satellite speaker system includes a side firing low mid driver mounted in a sub-enclosure which is vented into a second sub-enclosure through an acoustic resistance vent and to a third sub-enclosure through a variable aperture second vent. The vents further serve as pivots to allow the side-firing speaker to be rotated through a predetermined range, simultaneously varying the aperture of the second vent. The pivots are isolated by o-rings to provide an airtight seal to the sub-enclosures, as well as to provide vibration control. Third, fourth and fifth resistively damped vents allow the first and second sub-enclosure to establish acoustic communication with the environment. The front firing driver/s that reproduces the mid and high frequencies are mounted in a fourth sub-enclosure.

Abstract: A speaker system includes a body unit, a front panel slidably coupled to a front surface of the body unit, a first speaker unit that is provided on the front surface the body unit to output sound, and a second speaker unit that is provided on a rear surface of the front panel to output sound.

Abstract: A collapsible electro-acoustic transducer system (“CETS”) is described. The CETS system may include a base housing with at least one electro-acoustic transducer, where the base housing includes a base housing top and a base housing bottom, and a movable housing having at least one electro-acoustic transducer, where the movable housing is movably attached to the base housing. The CETS may also include an attaching element movably attaching the movable housing to the base housing, where the movable housing is configured to collapse within the base housing.

Abstract: A directional microphone assembly for a hearing aid is disclosed. The hearing aid has one or more microphone cartridge(s), and first and second sound passages. Inlets to the sound passages, or the sound passages themselves, are spaced apart such that the shortest distance between them is less than or approximately equal to the length of the microphone cartridge(s). A sound duct and at least one surface of a microphone cartridge may form each sound passage, where the sound duct is mounted with the microphone cartridge. Alternatively, each sound duct may be formed as an integral part of a microphone cartridge.

Abstract: A speaker system including in combination a speaker and surface mounting apparatus is disclosed. The speaker system has an adapter that secures the speaker system to the wall. A speaker box is secured to the adapter and has at least one speaker that is secured to at least one speaker portal wall of the speaker box, or speaker enclosure. A speaker portal wall is disposed in a plane that is oriented at an angle relative to the wall and is disposed outboard of the wall. A surface mounting adapter has a peripheral edge portion and a planar portion extending between the peripheral edge portion and the enclosure structure. Portions of at least four sides of the enclosure structure protrude from the planar portion of the wall. Other portions of at least four sides of the enclosure structure are recessed relative to the planar portion of the wall.

Abstract: The loudspeaker has a first pair of drivers arranged in a line, a center point along the line, wherein the pair of drivers are substantially centered about the center point with a center to center distance, d0, between the drivers in the first pair of drivers, whereby the maximum frequency with out high amplitude side lobes is equal to c/2d0, and at least a subsequent pair of drivers arranged in the line array with the first pair of drivers and substantially centered about the center point, wherein the subsequent pair of drivers are spaced such that the center to center distance between each driver in the subsequent pair, dn, is equal to 4nd0, where n=0 at the innermost pair of drivers and n increases by 1 with each pair of drivers sequentially added. Each pair of drivers for n>0 has a first order low pass filter with a frequency equal to 2c/dn.

Abstract: A surround sound system and method involving a surround sound tower (10) having planar speakers (11b); a base plate (20); and a structure for positioning (30) the surround sound tower on the base plate (20), the surround sound tower (10) being mounted on, and normal to, the positioning structure (30) for customizing sound direction and constructive interference patterns by interactively positioning the sound tower (10) and by modular usage of both sub-woofers (12a) and tweeters (13a), economizing floor space, especially in a home theater environment, the positioning structure (30) having a structure for indicating an angular rotation (40) of the surround sound tower (10) relative to the base plate (20) and a structure for facilitating rotation (50) of the angular rotation indicating structure (40).

Abstract: A pivoting panel-mount speaker assembly comprises a speaker housing. The speaker housing has a perimeter flange portion, an exterior housing wall extending rearwardly from the perimeter flange portion, and an interior curved track extending rearwardly from the perimeter flange portion. The interior curved track has an outward facing convex surface and an inward facing concave surface. The speaker assembly further comprises a speaker unit having a transducer element and a speaker frame supporting the transducer element. The speaker frame has an outward facing surface configured to slidably engage the inward facing concave surface of the housing interior curved track. The speaker assembly further comprises a speaker support member attached to the speaker unit. The speaker support member also has an inward facing surface configured to slidably engage the outward facing convex surface of the housing interior curved track.

Abstract: A horn or waveguide public address unit, enabling to adapt the dispersion characteristics of the horn or waveguide. The unit is provided with at least one profiling component (21a, 21b) constituting a removable dispersion shaper, capable of being mounted on the inner wall of the horn (13) or waveguide between the throat (17) and the mouth (19) thereof.

Abstract: A mounting bracket may be used to attach a device or component at a mounting location. The mounting bracket may comprise a an attachment portion having at least one tab portion that further comprises generally parallel first and second surfaces extending along a curved path. The tab portion may be designed so that the slot may be received at the mounting location so that, when installed, the first and second surfaces contact the interior and exterior surfaces, respectively. The tab portion, in cooperation with the slot, may accurately position and securely retain the mounting bracket at the mounting location.

Abstract: This invention provides a radiation boundary integrator (“RBI”) for integrating sound radiation from mid-range and high-frequency sources in multi-way loudspeakers. The RBI is a substantially solid boundary that is placed over the mid-range speakers to provide smooth, wave-guiding side walls to control the angular radiation of the high-frequency sound waves emanating from the high-frequency sound sources. To allow the mid-range frequency sound waves generated from mid-range sound sources to pass through the RBI, the RBI is designed with openings. To further prevent the possibility of having high-frequency sound radiate through the openings in the RBI, the RBI may be designed with porous material in the openings of the RBI. The porous material would be transparent to the mid-range sound radiation, but would prevent the high-frequency sound radiation from being disturbed by the openings in the RBI.

Abstract: An acoustic warning or alerting system for directing an audible warning signal to at least one intended recipient, while reducing the chance that the warning signal will be heard by others within the proximity of the system. The system includes a modulator for modulating an ultrasonic carrier signal with a processed audio signal, a driver amplifier for amplifying the modulated carrier signal, and a parametric array of acoustic transducers for projecting the modulated and amplified carrier signal through a propagation medium for subsequent regeneration of the audio signal along a pre-selected projection path. The parametric array of audio transducers operates by employing the nonlinear interaction between high frequency sound components and the propagation medium to generate at least one highly directional beam of lower frequency sounds within the propagation medium.

Abstract: A surround sound system and method involving a surround sound tower; a base plate; and a structure for positioning the surround sound tower on the base plate, the surround sound tower being mounted on, and normal to, the positioning structure for customizing sound direction and constructive interference patterns by interactively positioning the sound tower and/or at least one sound tower and by modular usage of tweeters, economizing floor space, especially in a home theater environment. The positioning structure may have a structure for indicating an angular rotation of the surround sound tower relative to the base plate and a structure for facilitating rotation of the angular rotation indicating structure.

Abstract: A door leaf includes a stiff, light structural part that maintains fed-in vibrational energy and, by flexural waves, propagates this energy in at least one active surface perpendicular to its thickness to distribute resonance mode vibration components over at least one surface, which has specified, preferred locations or sites within it for transducer devices, which are affixed on the structural part at one of the locations or sites to set the structural part into vibration and to allow it to resonate, thus creating an acoustic radiator that delivers an acoustic output signal when it vibrates in resonance, the front and/or the rear cover panel of the door leaf being part of the stiff, light structural component. The transducer(s) is/are situated between the cover panels.

Abstract: An articulating speaker assembly for the interior of a motor vehicle, which includes sidewall trim defining a pocket in the trim, includes a housing and at least one speaker operatively supported within the housing. The assembly includes at least one pivot arm having first and second ends. The first end is operatively connected to the housing and defines a rotational axis, and the second end is attached to the vehicle and defines a pivotal axis. The at least one pivot arm is adapted to pivot about the pivotal axis to selectively move and position the housing at each point along a path between a retracted position wherein said housing is operatively supported within the pocket and aligned substantially flush with the sidewall trim such that the sidewall trim and the housing are substantially co-planar in the retracted position of the housing, and an extended position outside the pocket.

Abstract: A speaker box mounting structure includes a panel provided with a plurality of speaker mounting bosses, and a speaker box provided with a plurality of lugs. An engaging projection projects from each of the bosses. The engaging projection has an enlarged engagement head which is expansively and contractively deformable. An annular elastic damper is retained by each of the lugs. The elastic dampers is fitted over the engaging projection between each boss and the enlarged engagement head for fixing the speaker box to the panel.

Abstract: A foldable speaker system, including an elongated base member having a first end and a second end; a first speaker member having a first pivoting end and being pivotally connected to the first end of the base member, wherein the first speaker member is pivotally movable between a first closed position co-linear with the base member and a second vertical position; and a second speaker member having a second pivoting end and being pivotally connected to the second end of the base member, wherein the second speaker member is pivotally movable between a first closed position co-linear with the base member and a second vertical position. The first and second speaker members in their first closed positions, respectively, substantially overlap the base member, so that the non-pivoting second ends of the first and second speakers are adjacent to each other.

Abstract: A loud speaker according to the invention is mountable within a receptacle. The loudspeaker includes a magnetic driver and a diagragm mounted to a frame. The froame includes a mounting member extending from a surface of the frame behind the flange plane. The mounting member is engagable in a notch formed in the receptacle for securing the speaker within the receptacle. The loudspeaker enclosure has perforated layer shaped to define its inner volume. A honeycomb layer surrounds that perforated layer; and semi-rigid layer surrounds the honeycomb layer and forms the exterior wall.

Abstract: System and techniques to movably attach speakers to a spa. A system includes a spa, and a speaker coupled with an exterior surface of the spa in proximity to a location where a spa cover resides when on the spa, the speaker being useable in connection with the spa cover without interference between the spa cover and the speaker.

Abstract: A combination speaker enclosure mounting structure includes a plurality of spherical enclosures, each spherical enclosures having two crossed openings at two opposite sides, and two receptacles respectively disposed in the crossed opening, and a plurality of fasteners adapted to secure the spherical enclosures to one another, for enabling the spherical enclosures to be adjusted to the desired angle relative to one another.

Abstract: The assembly comprises a loudspeaker drive unit having terminals for connection to an audio signal source. The drive unit has a chassis with a mounting ring which has first and second opposed surfaces for, respectively, abutment against a seating in a mounting ring and abutment by a retaining circlip. The mounting ring is retained in an aperture in, for example, a ceiling by spring clips. The design of the drive unit allows it to be substituted for the sealed halogen light bulb in a conventional light fitting having such a bulb. A simple and convenient way of mounting the loudspeaker, particularly in a ceiling in a room such as a kitchen or bathroom where space elsewhere is limited, is therefore provided. The invention also facilitates conversion between a light fitting to a speaker installation.

Abstract: Speaker device includes a main speaker unit and sub-speaker unit having their respective axes oriented in different directions. Signal processing device includes a processing unit for main speaker that supplies the main speaker unit with an, audio signal input to an input terminal, and a signal processing unit for sub-speaker including an adjustment section that adjusts a characteristic of the audio signal input to the input terminal. The signal processing unit for sub-speaker supplies the sub-speaker unit with the audio signal adjusted by the adjustment section.

Abstract: A wall mounting speaker assembly having a speaker unit, includes a stationary member mounted on a wall; a supporter supporting the speaker unit; a movable joint provided between the stationary member and the supporter, and combined with a vertical swiveling shaft and a horizontal tilting shaft, which make the speaker unit swivel and tilt; a lock provided on a bottom of the speaker unit; and a hook provided on the supporter to be engaged with the lock, preventing the speaker unit form moving upward. With this configuration, the present invention provides a wall mounting speaker assembly which can mount a speaker unit with a simple and convenient setup method without a screwing work, and has swiveling and tilting functions.

Abstract: A multichannel audio system for radiating sound to a listening area that includes a plurality of listening spaces. The audio system includes directional audio devices, positioned in a first of the listening spaces, close to a head of a listener, for radiating first sound waves corresponding to components of one of the channels and nondirectional audio devices, positioned inside the listening area and outside the listening space, distant from the listening space, for radiating sound waves corresponding to components of a second of the channels.

Abstract: A speaker assembly a speaker assembly that is readily mounted and dismounted from a mounting bar, and which also achieves reliable electrical connection in the same mounting connection. To mount the speaker, one pulls a plunger pin out, inserts a mounting boss into a swivel mount, and releases the plunger pin to lock the speaker onto the swivel mount. This action also inserts a jack into a receptacle, and completes the electrical connection of the speaker to the music source. The speaker is then rotated to the desired position and fixed in place by tightening a thumb screw.

Abstract: A directional microphone assembly for a hearing aid is disclosed. The hearing aid has one or more microphone cartridge(s), and first and second sound passages. Inlets to the sound passages, or the sound passages themselves, are spaced apart such that the shortest distance between them is less than or approximately equal to the length of the microphone cartridge(s). A sound duct and at least one surface of a microphone cartridge may form each sound passage, where the sound duct is mounted with the microphone cartridge. Alternatively, each sound duct may be formed as an integral part of a microphone cartridge.

Abstract: An orientation adjusting apparatus for a speaker set has a moving device, which is received in a housing, and includes a first motor, a second motor, a co-moving wheel, and an up and down movably frame biased upwards by springs. The first motor comes into contact with a top of the frame at a depressing wheel thereof. The second motor is secured to the frame, and has a second wheel. The co-moving wheel is connected to the frame. When the first, and the second motors are activated, the frame will be moved down by means of the depressing wheel for both the second wheel and the co-moving wheel to stick out from the bottom of the housing to come into contact with the ground, and the housing will be moved left and right by means of the second wheel with a rear support leg thereof as a pivot.

Abstract: A modular audio loudspeaker array system. The system includes a first speaker module, and a second speaker module, constructed and arranged to radiate sound waves responsive to audio signals. Sound waves radiated by the first speaker module and the sound waves radiated by the second speaker module combine to form a radiation pattern. The system further includes a positioning system, for positioning the first bass module relative to the second bass module at a plurality of fixed predetermined distances; an audio signal input terminal electronically for coupling the loudspeaker array to a source of the audio signals for receiving the audio signals; an audio signal processing device, electronically coupling the audio signal input terminal to the first bass module and to the second bass module, for processing the audio signals and transmitting the audio signals to the first speaker module and to the second loudspeaker module.

Abstract: An elliptical speaker system is provided for in-wall/in-ceiling mounting. The speaker system comprises an elliptical speaker frame or bracket defining a speaker front plane having a generally arcuate inner surface. First and second speaker components are mounted within the speaker frame, on opposing sides of the speaker inner surface. At least one of the speaker components may be translatable within the speaker frame.

Abstract: A speaker mounting structure is provided in which a speaker frame (11) is fixed to a mounting panel (P) by engaging latching hooks (24L, 24R) and a latching clip (26) provided on the speaker frame (11) with mounting holes (22, 23L, 23R) formed in the inner panel (P) of an automobile door. The latching hooks (24L, 24R) and the latching clip (26) are disposed inside the outer peripheral edges of annular seal members (16, 17) that are bonded to a mounting surface (11a) of the speaker frame (11) and are in intimate contact with the inner panel (P). As a result, even when water infiltrates to the speaker (C) side from an opening (21) or the mounting holes (22, 23L, 23R) of the inner panel (P), the seal members (16, 17) can block the water and prevent it from flowing to the passenger compartment side. It is thereby possible to reliably avoid ingress of water.

Abstract: A speaker system includes a first speaker; a second speaker; and a first spacer for separating the first speaker and the second speaker from each other so that the first speaker and the second speaker face each other. The first speaker and the second speaker are located so that opposing faces of the first speaker and the second speaker output sounds of an identical phase. The first speaker, the second speaker and the first spacer form a first sound path through which the sounds output from the opposing faces of the first speaker and the second speaker pass. The speaker system according to the present invention includes n number speakers and (n−1) number of spacers and can be arranged so that the opposing faces of even-numbered speakers and odd-numbered speakers output sounds of an identical phase.

Abstract: A tweeter support rack structure includes a tweeter body, a fixing base, and a support rack body. The tweeter body is fixed on the fixing base by a fixing screw. The fixing base has a top combined with the tweeter body, and a bottom combined with the support rack body. The bottom of the fixing base is provided with at least one locking ratchet. The support rack body has a top combined with the fixing base which may be rotated on the top of the support rack body. The top of the support rack body is provided with multiple locking teeth meshing with the locking ratchet of the fixing base.

Abstract: A speaker system comprises a housing that includes a front wall with a plurality of openings, and first and second exterior sidewalls. A plurality of vertically arranged speakers are each placed into an associated one of the plurality of openings and secured to the housing. A hemispherical concave interior wall is positioned in back of the plurality of speakers and within said first and second sidewalls to disperse and attenuate audio waves within the housing. The housing may also include a tuned, dampening bisector that is mounted to the hemispherical concave interior wall positioned in back of said plurality of speakers and within the first and second sidewalls. The bisector is preferably located at the center of the hemispherical concave interior wall. A rear exterior wall defines a back of the speaker system and the front wall defines a front of the speaker system.

Abstract: An elliptical speaker system is provided for in-wall/in-ceiling mounting. The speaker system comprises an elliptical speaker frame defining a speaker front plane having a generally arcuate inner surface. First and second speaker components are mounted within the speaker frame, on opposing sides of the speaker inner surface. At least one of the speaker components may be translatable within the speaker frame.

Abstract: A speaker box for a sport utility vehicle. The speaker box is pivotally mounted to the sports bar of the vehicle and can be selectively pivoted relative to the bar to a plurality of positions. In one position, the sound from the speakers of the speaker box is directed downwardly as in convention designs. However, unlike conventional designs, the speaker box and its sound can also be directed rearwardly of the vehicle for parties and other gatherings such as at campsites or on the beach. Further, the speaker box and its sound can be directed slightly forward toward the front of the vehicle if desired. In doing so, a saddle or cutout is provided in the middle of the speaker box so as not to unduly inhibit the driver's vision through the rear view mirror.

Abstract: An interchangeable loudspeaker assembly capable of pivoting the low-frequency and high-frequency transducers to provide directional sound while avoiding hindrance of sound waves by the loudspeaker frame.

Abstract: The loudspeaker and method provide a driver of a loudspeaker that is movable parallel to a direction of movement to produce sound waves. A reflector is mounted in front of a diaphragm of the driver for reflecting sound waves from the driver. The direction of movement is at a non-zero acute angle to the horizontal or to an external support plane that supports the loudspeaker.

Abstract: A speaker rack for use with spas including a first and second member with the second member comprising generally extending members. The first member is coupled to the generally extending members of the second member. This first member allows for support, helps an individual move the speaker rack into different positions easily and acts as a place to hang towels, clothing and the like. Multi-position detents attach to the second member and allow for the speaker rack to be placed in an extreme upward position, an extreme downward position and positions in between. Speakers that can be swivel and pivotally mounted attach to speaker attachment means on the generally extending members of the second member and speaker wiring may run through an aperture in the second member and attach to an output device allowing for entertainment while in or around the spa.

Abstract: An output section, consisting of a pair of loudspeakers disposed adjacently to each other, is installed inside a seatback of a designated seat. Sound output surfaces of respective loudspeakers face a designated person sitting on the designated seat. It is hence easy to secure a required distance for obtaining clear acoustic image localization in accordance with the size of loudspeakers cooperatively constituting the output section.

Abstract: A mounting system for loudspeakers is provided. In general, the system comprises a flexible arm having a first end and a second end. The first end of the flexible arm is suitably mounted to the loudspeaker. The second end of the flexible arm is suitably mounted to a surface. The surface may comprise a wall, another loudspeaker and/or a computer monitor. Various combinations and arrangements of speakers are disclosed, including mounting systems advantageously configured to provide surround sound experiences.

Abstract: A biaxial parametric speaker having at least two different axes of sound propagation. The speaker includes a first parametric emitter including an ultrasonic emitter surface having a primary direction of propagation along a first orientation and a second parametric emitter including an ultrasonic emitter surface having a primary direction of propagation along a second orientation. The first parametric emitter is physically coupled to the second parametric emitter such that the first and second orientations do not coincide, thereby providing for relative angular displacement of the respective first and second orientations of propagation. Electronic contacts are attached to the respective first and second parametric emitters for coupling to a parametric signal source capable of generating parametric emissions from the respective emitters which decouple in air to generate audio output along each of the respective first and second orientations.

Abstract: A loudspeaker apparatus 1 includes a loudspeaker unit 3 and an installation device 2. The loudspeaker unit 3 includes drivers 22 and 23 and an enclosure for the drivers composed of front and rear members 20 and 21. The loudspeaker unit is detachably mounted to an installation device 2, which, in turn, is secured to an installation surface 11 to which the loudspeaker apparatus is to be installed. The loudspeaker unit is mounted rotatable about its center axis 25. The drivers have respective sound radiation center axes 22a and 23a, which are oriented to intersect the center line 25 at a predetermined angle &thgr;. Thus, the direction in which the drivers radiate sound can be changed by rotating the loudspeaker unit about the center axis.

Abstract: A super-directional loudspeaker is provided, which makes for a listener to receive an audible sound at a high sound pressure with a compact size. This loudspeaker is comprised of a supporting member having a concave surface, and electro-acoustic transducer elements fixed to the supporting member. The elements are designed to receive an electrical input signal and to produce acoustic vibrations according to the electrical input signal thus received, thereby emitting directional ultrasonic waves in the air. The elements are arranged along the concave surface of the supporting member in such a way that the directional ultrasonic waves emitted by the elements propagate in the air to converge on a listening point in front of the concave surface. It is preferred that the curvature of the concave surface of the supporting member is adjustable according to the location of the listener.