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.

A method for monitoring an aircraft engine vane wheel (22), which includes: acquiring at least one time signal relative to moments when the vane wheel blades (23) pass in front of a sensor (21); determining a common flight phase of the aircraft; for each flight in a series of flights of the aircraft, correlating at least part of each time signal with a predetermined flight phase; and for each blade (23), each flight, and each predetermined flight phase, measuring the mean position (24C), the so-called “balance position”, of the top of the blade. The invention also relates to a device for implementing such a method. One advantage of the invention is providing a diagnosis of the blades using a small number of sensors and low computing power.

In various embodiments, an air quality-monitoring system (100) may include at least one sensor (106) configured to detect operation of a mechanism (110) within or at a boundary of an indoor environment. The mechanism may be external to an air purifier (102) associated with the indoor environment. The system may include a persistent memory (124) for storing data about the indoor environment observed by the at least one sensor (106). A controller (104) may be communicatively coupled with the at least one sensor and configured to: assemble the data into an air quality profile associated with that environment; determine, based on a signal from the at least one sensor and on the air quality profile, a likelihood that operation of the mechanism will cause a measure of air quality within the indoor environment to fail one or more air quality criteria; and selectively provide, based on the likelihood, an indication that operation of the mechanism will cause the measure of air quality within the indoor environment to fail the one or more air quality criteria.

In various embodiments, an air quality-monitoring system (100) may include at least one sensor (106) configured to detect operation of a mechanism (110) within or at a boundary of an indoor environment. The mechanism may be external to an air purifier (102) associated with the indoor environment. The system may include a persistent memory (124) for storing data about the indoor environment observed by the at least one sensor (106). A controller (104) may be communicatively coupled with the at least one sensor and configured to: assemble the data into an air quality profile associated with that environment; determine, based on a signal from the at least one sensor and on the air quality profile, a likelihood that operation of the mechanism will cause a measure of air quality within the indoor environment to fail one or more air quality criteria; and selectively provide, based on the likelihood, an indication that operation of the mechanism will cause the measure of air quality within the indoor environment to fail the one or more air quality criteria.

A system quantifies listener envelopment in a loudspeakers-room environment. The system includes a binaural detector that receives frequency modulated audible noise signals from multiple loudspeakers. The binaural detector generates detected signals that are analyzed to determine an objective listener envelopment. The envelopment is based on binaural activity of one or more sub-bands of the detected signal.

A system quantifies listener envelopment in a loudspeakers-room environment. The system includes a binaural detector that receives frequency modulated audible noise signals from multiple loudspeakers. The binaural detector generates detected signals that are analyzed to determine an objective listener envelopment. The envelopment is based on binaural activity of one or more sub-bands of the detected signal.

A device, system and method for monitoring a cable for a physical disturbance is disclosed. The device includes at least one pair of acoustic transducers, the pair comprising a first acoustic conductor monitoring transducer and a second ambient transducer. The acoustic conductor monitoring transducer is in acoustic contact with an acoustic conductor to be monitored by the device, with the transducers being arranged such that an ambient acoustic signal is common to both transducers. The device further includes a circuit element, with each transducer being connected to an input of the circuit element, the circuit element being arranged to output a difference between the input signals from the transducers. An alarm triggering module is connected to an output of the circuit element, the module being operable to trigger an alarm when the output signal received from the circuit element exceeds a predefined threshold value.

A device, system and method for monitoring a cable for a physical disturbance is disclosed. The device includes at least one pair of acoustic transducers, the pair comprising a first acoustic conductor monitoring transducer and a second ambient transducer. The acoustic conductor monitoring transducer is in acoustic contact with an acoustic conductor to be monitored by the device, with the transducers being arranged such that an ambient acoustic signal is common to both transducers. The device further includes a circuit element, with each transducer being connected to an input of the circuit element, the circuit element being arranged to output a difference between the input signals from the transducers. An alarm triggering module is connected to an output of the circuit element, the module being operable to trigger an alarm when the output signal received from the circuit element exceeds a predefined threshold value.

Disclosed are a device and a method for testing impedance characteristic and expansion performance of a sound absorption material. The device includes a first cavity and a second cavity which are both sealed. The first cavity is communicated with the second cavity through a slit channel. The second cavity is used for placing a sound absorption material therein. The device further includes a sound excitation source whose sounding face is located in the first cavity and used to provide a testing sound pressure. The device further includes two sound pickup sensors whose sound pickup surfaces are respectively arranged in the first cavity and the second cavity and respectively used to detect sound pressure in the first cavity and the second cavity. The device further includes a material for enclosing the first cavity and the second cavity is a hard sound insulation material.