An acoustic measuring device suitable for performing measurements on a surface in contact with a flow. This acoustic measuring device comprises an acoustic surface delimiting a cavity, which has an axis of revolution, which comprises a recess centered with respect to the axis of revolution, configured to house an acoustic sensor and which, in a longitudinal plane passing through the axis of revolution, follows a logarithmic profile which extends from a first edge separating the recess and the acoustic surface.

An acoustic measuring device suitable for performing measurements on a surface in contact with a flow. This acoustic measuring device comprises an acoustic surface delimiting a cavity, which has an axis of revolution, which comprises a recess centered with respect to the axis of revolution, configured to house an acoustic sensor and which, in a longitudinal plane passing through the axis of revolution, follows a logarithmic profile which extends from a first edge separating the recess and the acoustic surface.

A wave-source-direction estimation device includes: a plurality of input units that acquires, as input signals, electrical signals based on waves detected by a plurality of sensors; a signal selection unit that selects a plurality of pairs that are each a combination of two input signals from among a plurality of the input signals; a relative delay time calculation unit that calculates, as relative delay times, arrival time differences of the waves at the sensors that are supply sources of the two input signals composing each of the pairs, for each wave source direction; and an integrated-estimated-direction-information calculation unit that generates per-frequency estimated direction information for each of the pairs using the input signals composing each of the pairs and the relative delay times of each of the pairs and generates integrated estimated direction information by assigning a weight to and integrating the estimated direction information on all the pairs.

An acoustic reflector for a microphone to measure flyover noise generated by an aircraft. The microphone is configured to measure flyover noise generated by an aircraft flying on a preset path. The acoustic reflector includes at least a central portion having the shape of an ellipse having a major axis and a plurality of peripheral portions distributed around the central portion. The acoustic reflector allows edge effects to be attenuated at the low frequencies of the noise to be measured.

A gas sensor for detecting a gas in an environment is disclosed. The gas sensor comprises a housing having a cavity and a vent hole within the housing and a distributed element resonator within the cavity. The cavity includes a bottom surface and a top surface, and the housing is configured to receive the gas from the environment into the cavity through the vent hole. The distributed element resonator has an input terminal configured to receive a radio frequency input signal and an output terminal configured to produce an output signal.

A gas sensor for detecting a gas in an environment is disclosed. The gas sensor comprises a housing having a cavity and a vent hole within the housing and a distributed element resonator within the cavity. The cavity includes a bottom surface and a top surface, and the housing is configured to receive the gas from the environment into the cavity through the vent hole. The distributed element resonator has an input terminal configured to receive a radio frequency input signal and an output terminal configured to produce an output signal.

This storage unit is configured to store an outside-of-panel acoustic transfer function that is an acoustic transfer function involving an airborne sound that is a sound emitted from a sound source located outside a panel member and propagated through the air to an outer surface of the panel member, and a panel transmission function that is an acoustic transfer function from the outer surface of the panel member to an inner surface of the panel member. This sound transmission analyzing unit is configured to calculate, based on the outside-of-panel acoustic transfer function and the panel transmission function, an acoustic transfer function from the sound source via the air to the inner surface of the panel member.

Systems and methods for reducing vibrations perceived by a human due to an artificial heart valve include a vest that is wearable around a torso of the human, a plurality of sensors mounted to the vest, a plurality of vibration-generating actuators mounted to the vest, and a controller. The plurality of sensors detects vibrations in the human generated by the artificial heart valve. The controller is operable to receive signals representing the detected vibrations from the plurality of sensors, and is operable to produce anti-vibration signals that substantially attenuate the detected vibrations. A first sensor of the plurality of sensors is located near a first vibration-generating actuator of the plurality of vibration-generating actuators to form a sensor/actuator set. In the sensor/actuator set, the anti-vibration signals generated by the controller for the first vibration-generating actuator correspond to the vibrations detected by the first sensor.

Systems, methods, and apparatus for corona detection using audio data are provided. In one example embodiment, the method includes obtaining, by one or more computing devices, audio data indicative of audio associated with an electrical system for at least one time interval. The method includes partitioning, by the one or more computing devices, the audio data for the time interval into a plurality of time windows. The method includes determining, by the one or more computing devices, a signal indicative of a presence of corona based at least in part on audio data collected within an identified time window of the plurality of time windows relative to audio data collected for a remainder of the time interval.

The present invention relates to a vibration sensor comprising a pressure generating element for generating pressure differences between a first and a second volume in response to vibrations of the vibration sensor, the first and second volumes being acoustically sealed from each other, and a pressure transducer for measuring pressure differences between the first and second volumes. The present invention also relates to an associated method for detecting vibrations.