A speaker comprises a housing, a transducer residing inside the housing, and at least one sound guiding hole located on the housing. The transducer generates vibrations. The vibrations produce a sound wave inside the housing and cause a leaked sound wave spreading outside the housing from a portion of the housing. The at least one sound guiding hole guides the sound wave inside the housing through the at least one sound guiding hole to an outside of the housing. The guided sound wave interferes with the leaked sound wave in a target region. The interference at a specific frequency relates to a distance between the at least one sound guiding hole and the portion of the housing.

A speaker comprises a housing, a transducer residing inside the housing, and at least one sound guiding hole located on the housing. The transducer generates vibrations. The vibrations produce a sound wave inside the housing and cause a leaked sound wave spreading outside the housing from a portion of the housing. The at least one sound guiding hole guides the sound wave inside the housing through the at least one sound guiding hole to an outside of the housing. The guided sound wave interferes with the leaked sound wave in a target region. The interference at a specific frequency relates to a distance between the at least one sound guiding hole and the portion of the housing.

A speaker comprises a housing, a transducer residing inside the housing, and at least one sound guiding hole located on the housing. The transducer generates vibrations. The vibrations produce a sound wave inside the housing and cause a leaked sound wave spreading outside the housing from a portion of the housing. The at least one sound guiding hole guides the sound wave inside the housing through the at least one sound guiding hole to an outside of the housing. The guided sound wave interferes with the leaked sound wave in a target region. The interference at a specific frequency relates to a distance between the at least one sound guiding hole and the portion of the housing.

A semi-wave transducer is provided that comprises a circular or elliptic transduction shell that has sidewalls captured between identical opposing upper and lower circular or elliptic conical segments (platens), each having a surface geometry of a radially symmetric wave shape that includes a center region and a rim wherein the distance between the center region of the upper and lower platens greater than the distance between the rims of the upper and lower platens. In some embodiments, the surface geometry of the platens may be a jinc function or a recurve function.

A semi-wave transducer is provided that comprises a circular or elliptic transduction shell that has sidewalls captured between identical opposing upper and lower circular or elliptic conical segments (platens), each having a surface geometry of a radially symmetric wave shape that includes a center region and a rim wherein the distance between the center region of the upper and lower platens greater than the distance between the rims of the upper and lower platens. In some embodiments, the surface geometry of the platens may be a jinc function or a recurve function.

A sound source for acoustic communication, navigation, and networking of an underwater glider may include a cylindrical body, a rigid front section disposed anteriorly to the cylindrical body, a plurality of metal rods, a resonant pipe surrounding the rods, and a rod-mounted piezo-ceramic transducer disposed between the body and the front section. Each rod may be attached at a first end to an anterior portion of the body and at a second end to a posterior portion of the front section. The pipe may be disposed between the body and the front section. The transducer may be disposed within the pipe. A posterior end of the pipe may be separated from the anterior portion of the body by a first orifice, and an anterior end of the pipe may be separated from the posterior portion of the front section by a second orifice.

A display device including a display panel including a substrate and a pixel array layer disposed on a first surface of the substrate, a sound generation device disposed on a second surface of the substrate opposite to the first surface of the substrate, and a circuit board disposed on the second surface of the substrate, in which the circuit board includes a first hole overlapping the sound generation device.

An ultrasonic generator that is capable of increasing output sound pressure is provided. An ultrasonic generating element is accommodated in an accommodation space that is formed by a first case member and a second case member. The ultrasonic generating element is secured to the first case member via a plurality of first supporting members. The first supporting members are provided so that, in a first acoustic path that includes a space formed between a bottom surface of the ultrasonic generating element and a top surface of the first case member and that extends to sound-wave emission holes, a transverse section of the acoustic path has a portion that becomes smaller than another portion thereof.

An ultrasonic generator that is capable of increasing output sound pressure is provided. An ultrasonic generating element is accommodated in an accommodation space that is formed by a first case member and a second case member. The ultrasonic generating element is secured to the first case member via a plurality of first supporting members. The first supporting members are provided so that, in a first acoustic path that includes a space formed between a bottom surface of the ultrasonic generating element and a top surface of the first case member and that extends to sound-wave emission holes, a transverse section of the acoustic path has a portion that becomes smaller than another portion thereof.

In one embodiment, acoustic devices are formed on a substrate which is then placed on a first HAF layer, a screen, and a second HAF layer. The layers of HAF each have apertures aligned with acoustic ports of the devices. The substrate is heated such that the first layer of HAF adheres to the substrate and the screen and the second layer of HAF adheres to the screen. The substrate is cut to separate the devices into modules. In other embodiments, a waterproof membrane covering the acoustic port of an acoustic module may be bonded to a screen to form a gap such that it moves under pressure until restrained by the screen. In still other embodiments, back volume covers for acoustic devices are formed by stacking and heating a first HAF layer, a glass-reinforced epoxy laminate layer, a second HAF layer, and a top layer on a substrate.