A horn for speakers includes a horn body including: a first opening located in a first end portion and having a circular shape; a second opening located in a second end portion and having a shape different from the circular shape; and a sound path connecting the first opening and the second opening. In a cross section including a central axis of the horn body, an inner surface of the sound path flares out in a quartic curve from the first opening toward the second opening. A length (L2) from the first end portion to the second end portion of the horn body is at least 0.8 times as large as a radius (R) of the first opening.

A horn for speakers includes a horn body including: a first opening located in a first end portion and having a circular shape; a second opening located in a second end portion and having a shape different from the circular shape; and a sound path connecting the first opening and the second opening. In a cross section including a central axis of the horn body, an inner surface of the sound path flares out in a quartic curve from the first opening toward the second opening. A length (L2) from the first end portion to the second end portion of the horn body is at least 0.8 times as large as a radius (R) of the first opening.

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.

An acoustic lens includes: an elastomer substrate; and a filler which is dispersed in the elastomer substrate and has an average maximum length of 5 m to 100 m and an average maximum diameter of 0.01 m to 1 m.

A multi-function sound chamber for a handheld barcode reader may include the ability to (i) amplify or otherwise efficiently project an audible signal generated by a buzzer of the barcode reader to sound window(s), and (ii) provide stiffening support to a printed circuit board (PCB) on which an electromechanical switch is mounted that a trigger of the handheld barcode reader engages when activated by a user of the reader. The sound chamber may provide other functions, including isolating light between good/bad read signals and battery level status. Another function may include reducing electrostatic discharge (ESD) by providing a high-impedance seal around connecting screws. Another function may include retention of the PCB by providing a pocket with a compliant material to retain a top or other edge of the PCB. By having the sound chamber perform multiple functions, the barcode reader may be produced more efficiently and cost effectively.

An ultrasonic wave output device includes an ultrasonic wave generator, a horn and a holder. The ultrasonic wave generator is configured to output an ultrasonic wave from a sound wave output surface in a predetermined propagation direction. The horn surrounds a space, which is located on a front side of the at least one ultrasonic wave generator in the propagation direction. The horn is configured such that a size of the space, which is surrounded by the horn, is progressively increased toward the front side in the propagation direction. The holder is placed between the ultrasonic wave generator and the horn and is made of a softer material, which is softer than a material of the ultrasonic wave generator. The holder is configured to hold the ultrasonic wave generator in an unarrested state where an outer peripheral edge of the sound wave output surface is not arrested.

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 multi-function sound chamber for a handheld barcode reader may include the ability to (i) amplify or otherwise efficiently project an audible signal generated by a buzzer of the barcode reader to sound window(s), and (ii) provide stiffening support to a printed circuit board (PCB) on which an electromechanical switch is mounted that a trigger of the handheld barcode reader engages when activated by a user of the reader. The sound chamber may provide other functions, including isolating light between good/bad read signals and battery level status. Another function may include reducing electrostatic discharge (ESD) by providing a high-impedance seal around connecting screws. Another function may include retention of the PCB by providing a pocket with a compliant material to retain a top or other edge of the PCB. By having the sound chamber perform multiple functions, the barcode reader may be produced more efficiently and cost effectively.

A desktop device comprises a housing having a bottom side configured to face a surface on which the device is to be placed, such as a desktop, and a front side configured to face a user of the device. A down-firing speaker is placed inside the housing. A speaker port is disposed on the bottom side of the housing. A horn assembly on the housing is arranged to define a speaker horn in combination with the surface on which the device is placed.

A desktop device comprises a housing having a bottom side configured to face a surface on which the device is to be placed, such as a desktop, and a front side configured to face a user of the device. A down-firing speaker is placed inside the housing. A speaker port is disposed on the bottom side of the housing. A horn assembly on the housing is arranged to define a speaker horn in combination with the surface on which the device is placed.