Supercoupling waveguides are provided in which acoustic impedance at an acoustic input port matches the acoustic impedance at an acoustic output port, where the acoustic path extending from the acoustic input port to the acoustic output port has a variable length. The supercoupling waveguides may be used in methods of sensing and measuring, and may be incorporated into sensors.

A system for controlling sonar beam shapes is provided. The system comprises at least one sonar transducer element having an emitting face. The at least one sonar transducer element is configured to generate a sonar beam having a path. The system also comprises a horn that is configured to rest within the path of the sonar beam. The horn is configured to reform a beam shape of the sonar beam.

A method of designing an acoustic waveguide in which acoustic waves travelling along the waveguide are treated as exhibiting single parameter behaviour, and in which the waveguide provides a boundary confining the acoustic waves as they travel along the wave propagation path and has two substantially parallel, primary surfaces spaced apart a distance less than a wavelength of a high frequency acoustic wave. The primary surfaces may be planar, curved, or a combination of planar portions and curved portions.

A flow meter includes a pair of ultrasonic transducers. Each transducer includes a housing, a piezoelectric crystal disposed within the housing, and a mini-horn array coupled to the housing. The mini-horn array, which may be formed via a 3D printing technique, includes an opening-free enclosure, a closed cavity inside the enclosure, and a plurality of horns enclosed within the closed cavity. The horns include a horn base portion adjacent to a proximal end surface of the cavity and a horn neck portion that extends from the base portion in a direction away from the piezoelectric crystal and towards a distal end surface of the cavity. The horn neck portions are separated by spaces within the cavity, wherein the spaces between the horn necks may be filled with powder.

A robotic cleaning appliance includes a housing to which is coupled a surface treatment item and a sensor assembly with first and second transducers and an acoustic interface. The first sonic transducer transmits sonic signals through an acoustic interface and out of a first acoustic opening toward a surface beneath the robotic cleaning appliance. The sonic signals reflect from the surface as corresponding returned signals received by the second sonic transducer via a second acoustic opening port of the acoustic interface. A first annular ring is defined around the first acoustic opening port and a second annular rings is defined around the second acoustic opening port. The annular ring attenuate direct path echoes between the acoustic opening ports. The first and second acoustic opening ports are coupled the first and sonic transducers, respectively, via first and second horns; and the horns are tilted from orthogonal with the surface.

A loudspeaker comprising: an acoustic diaphragm having front and rear surfaces, the acoustic diaphragm in use being driven so as to vibrate and radiate acoustic waves from its front surface in a forward direction away from the loudspeaker and from its rear surface in a rearward direction, and a drive unit located rearwardly or to the front/outside of the diaphragm, there being at least one open duct leading in a rearward direction away from the diaphragm, in which the at least one open duct has a cross-sectional area which decreases in the rearward direction, and in which acoustic waves radiated from the rear surface of the diaphragm pass through the open duct before contacting a front surface of an acoustic metamaterial absorber located generally behind the drive unit and immediately to the rear of the duct.

A speaker system including an enclosure, a first acoustic driver engaged with the enclosure, and two or more horns configured to output a sound from the first acoustic driver to a front plane of the enclosure. In one embodiment, the two or more horns may be folded and planar. In one embodiment, the speaker system may include a second acoustic driver, which may be installed above or below the first acoustic driver. The second acoustic driver may be larger or smaller or the same size when compared to the first acoustic driver.

A system for controlling sonar beam shapes is provided. The system comprises at least one sonar transducer element having an emitting face. The at least one sonar transducer element is configured to generate a sonar beam having a path. The system also comprises a horn that is configured to rest within the path of the sonar beam. The horn is configured to reform a beam shape of the sonar beam.

This device consists of a hollow triangular pyramid shaped speaker mounting system that is divided into three cells. The device mounts into a corner of a structural space at the convergence of three plane surfaces such as two adjacent walls and the ceiling or the floor. The device would divide the acoustical waves from a speaker into three segments where diffusers would channel them into the pyramid toward the apex. A wave reverser would send the waves back toward the open base of the pyramid. When the three sound waves exit the device, they would merge and continue expanding along each of the three plane surfaces in the hosting structural space. Each segment of the sound waves would follow a path that takes the form of a folded horn. That would provide for a very large expansion of the sound waves coming from this device.

An acoustic wave generator including a stack having a plurality of first layers configured to receive electrical and/or magnetic energy and a plurality of second layers configured in contact with the plurality of first layers, the plurality of second layers comprising one or more materials configured to change mechanical properties when electrical and/or magnetic energy is applied thereto. The generator further having at least one source configured in operational communication with the plurality of first layers and configured to supply at least one of phased electrical and/or magnetic energy to the plurality of first layers, wherein the stack is configured to (i) generate phased acoustic energy and (ii) at least one of amplify and store the generated phased acoustic energy in a first state and release said generator acoustic energy in a second state.