A thermophone includes an inner core and an outer shell coaxial with the inner core. The inner core and outer shell enclose a volume filled with gas. A pair of posts extend radially from the inner core to the outer shell and extend longitudinally between the inner core and the outer shell. At least one longitudinal slot is formed along the outer shell and a fluid seal covers the slot. A thermoacoustic active element is disposed in the volume and heated by modulated current to generate alternating pressure on the outer shell and produce acoustic signals.

A thermophone includes an inner core and an outer shell coaxial with the inner core. The inner core and outer shell enclose a volume filled with gas. A pair of posts extend radially from the inner core to the outer shell and extend longitudinally between the inner core and the outer shell. At least one longitudinal slot is formed along the outer shell and a fluid seal covers the slot. A thermoacoustic active element is disposed in the volume and heated by modulated current to generate alternating pressure on the outer shell and produce acoustic signals.

A hydrophone used for measuring acoustic energy from a high frequency ultrasound transducer, or a method of manufacturing the membrane hydrophone. The membrane assembly is supported by the frame and comprises a piezoelectric. The hydrophone also includes an electrode pattern formed within the piezoelectric to define an active area. In addition, the hydrophone includes a built in-situ coaxial layer connected to the active area.

A hydrophone used for measuring acoustic energy from a high frequency ultrasound transducer, or a method of manufacturing the membrane hydrophone. The membrane assembly is supported by the frame and comprises a piezoelectric. The hydrophone also includes an electrode pattern formed within the piezoelectric to define an active area. In addition, the hydrophone includes a built in-situ coaxial layer connected to the active area.

A system for providing magnetic field audio signals to a receiver in an aquatic environment. The system includes an audio source configured to provide an electronic audio signal, and an induction loop amplifier configured to receive the electronic audio signal and convert the received electronic audio signal into a current. The system further includes a wire loop connected with the induction loop amplifier, the wire loop bounding at least part of the aquatic environment and around the receiver in the aquatic environment, the wire loop producing a magnetic field from the current to generate an audio frequency induction loop to transmit the electronic audio signal to the receiver in the aquatic environment.

A wireless audio streaming system for swimmers and underwater applications uses directional transmission antennas, one or more reception antennas worn on a user, and a combination of radio frequency and near-field magnetic induction communication, for streaming audio to a swimmer, buffering the streamed audio, and allowing the user to play the audio on a wireless, waterproof headset.

A wireless audio streaming system for swimmers and underwater applications uses directional transmission antennas, one or more reception antennas worn on a user, and a combination of radio frequency and near-field magnetic induction communication, for streaming audio to a swimmer, buffering the streamed audio, and allowing the user to play the audio on a wireless, waterproof headset.

The present disclosure discloses an acoustic output apparatus including at least one acoustic driver, a controller, and a supporting structure. The at least one acoustic driver may be configured to output sounds through at least two sound guiding holes. The at least two sound guiding holes may include a first sound guiding hole and a second sound guiding hole. The controller may be configured to control a phase and an amplitude of the sounds generated by the at least one acoustic driver using a control signal such that the sounds output by the at least one acoustic driver through the first and second sound guiding holes have opposite phases. The supporting structure may be provided with a baffle and configured to support the at least one acoustic driver such that the first and second sound guiding holes are located on both sides of the baffle.

The present disclosure discloses an acoustic output apparatus including at least one acoustic driver, a controller, and a supporting structure. The at least one acoustic driver may be configured to output sounds through at least two sound guiding holes. The at least two sound guiding holes may include a first sound guiding hole and a second sound guiding hole. The controller may be configured to control a phase and an amplitude of the sounds generated by the at least one acoustic driver using a control signal such that the sounds output by the at least one acoustic driver through the first and second sound guiding holes have opposite phases. The supporting structure may be provided with a baffle and configured to support the at least one acoustic driver such that the first and second sound guiding holes are located on both sides of the baffle.

An image capture device includes an audio depression formed into the housing with a drainage microphone mounted therein. A cover protects the drainage microphone disposed beneath the cover from an environment external to the image capture device. The cover and audio depression define a drainage channel extending from a channel entrance, through a channel volume, and out a channel exit. The surface area of the opening of the channel entrance is proportioned relative to the channel volume such that the ratio of the surface area to volume is greater than ten percent. This allows the cover to shift resonance outside of a desired frequency band.