A foldable display device includes: a first display panel including a first substrate and a first pixel array layer which is disposed on a first surface of the first substrate; a second display panel including a second substrate and a second pixel array layer which is disposed on a first surface of the second substrate; and a first sound generator disposed between a second surface of the first display panel opposite to the first surface of the first display panel and a second surface of the second display panel opposite to the first surface of the second display panel, where the first sound generator outputs first sound by vibrating at least one of the first and second display panels.

A sensor including one or more transistors; and one or more sensing elements, wherein an edge behaves as moving gate of said one or more transistors, an electric field is applied to said edge, said one or more transistors is/are biased, said one or more sensing elements is/are flexible, source and drain wells of said one or more transistors can be coplanar or stacked, said edge can move in a lateral or a parallel direction with respect to a transistor current, said edge can move in a vertical or a perpendicular direction with respect to said transistor current, and the magnitude of the change in said drain current determines the sensitivity.

An air-pulse generating device includes a membrane structure, a valve structure, and a cover structure. A chamber is formed between the membrane structure, the valve structure and the cover structure. An air wave vibrating at an operating frequency is formed within the chamber. The valve structure is configured to be actuated to perform an open-and-close movement to form at least one opening. The at least one opening connects air inside the chamber with air outside the chamber. The open-and-close movement is synchronous with the operating frequency.

An air-pulse generating device includes a membrane structure, a valve structure, and a cover structure. A chamber is formed between the membrane structure, the valve structure and the cover structure. An air wave vibrating at an operating frequency is formed within the chamber. The valve structure is configured to be actuated to perform an open-and-close movement to form at least one opening. The at least one opening connects air inside the chamber with air outside the chamber. The open-and-close movement is synchronous with the operating frequency.

Aspects of the present disclosure describe DFOS/DAS systems, methods, and structures that employ active microphones to enhance DAS operational capabilities by using an active circuit to amplify acoustic signals including voice(s). The circuit includes a microphone to collect acoustic signal(s) resulting from voice signals in the environment, and a speaker or a vibration device driven by an amplifier. The circuit can be clipped onto the fiber, with direct contact through the speaker or vibration device. A microcontroller may advantageously be employed to control the circuit for reduced power consumption, by detecting activities locally and only enabling the speaker when needed. The microcontroller may also send other information such as battery status to the DFOS interrogator through vibration codes.

Embodiments of the present invention provide methods, computer program products, and systems. Embodiments of the present invention can dynamically generate audio for one or more images associated with a location based on contextual information that satisfies a request. Embodiments of the present invention can embed the generated audio into the one or more images. Embodiments of the present invention can then display the one or more images with the embedded audio on a user device.

A pressure wave-generating device having a support and a heating element film that is disposed over the support and that is configured to generate heat by energization, and the heating element film has a porous metal structure.

A thermoacoustic device includes a loop tube in which a working gas is sealed; a stack in which a temperature gradient is generated in a tube axis direction of the loop tube, the stack being provided in the loop tube; and a diaphragm structure including a diaphragm provided in the loop tube and an operation unit, the diaphragm having a surface extending in a direction intersecting the tube axis direction and being configured to vibrate with a component of vibration in the tube axis direction, and the operation unit being configured to apply a physical quantity that is required, to the diaphragm to change a rigidity of the diaphragm in the tube axis direction.

Described herein are methods and systems of distributed acoustic sensing, such as in an urban or metropolitan area involving a dedicated and established fibre optic communications network including a data centre. In general, the disclosed method and system includes the steps of (a) selecting an optical fibre cable installation having a path extending across a selected geographical area, the optical fibre cable installation including a bundle of optical fibres and forming part of a fibre-optic communications network, (b) determining characteristics associated with the optical fibre and/or the selected optical fibre installation, (c) transmitting outgoing light in the optical fibre, (d) receiving reflected light back scattered along the optical fibre, and (e) based on the reflected light and the determined characteristics, generating an alert signal representative of an acoustic event. The disclosed method and system are applied to detect acoustic events near or within the selected geographical area.

Methods and apparatus to communicate via a welding arc are disclosed. An example welding-type power supply includes a power converter, a weld monitor, and an arc modulator. The power converter outputs welding power to sustain a welding-type arc at a welding-type torch. The weld monitor monitors one or more aspects of a weld performed using the welding-type arc and the welding-type torch, and selects an audio message based on the one or more aspects. The arc modulator configured to modify the welding-type arc to output the selected audio message as a plasma speaker.