Techniques are provided for audio-based detection and tracking of an acoustic source. A methodology implementing the techniques according to an embodiment includes generating acoustic signal spectra from signals provided by a microphone array, and performing beamforming on the acoustic signal spectra to generate beam signal spectra, using time-frequency masks to reduce noise. The method also includes detecting, by a deep neural network (DNN) classifier, an acoustic event, associated with the acoustic source, in the beam signal spectra. The DNN is trained on acoustic features associated with the acoustic event. The method further includes performing pattern extraction, in response to the detection, to identify time-frequency bins of the acoustic signal spectra that are associated with the acoustic event, and estimating a motion direction of the source relative to the array of microphones based on Doppler frequency shift of the acoustic event calculated from the time-frequency bins of the extracted pattern.

An ultrasonic detection circuit includes a transmitter circuit that provides excitation signals to an ultrasonic transducer during an excitation interval. A control circuit includes a port to receive a command. The control circuit controls the frequency and the duty cycle of the excitation signals of the transmitter circuit during the excitation interval. The control circuit generates a first excitation signal sequence of the excitation interval followed by a first monitoring period to receive a first echo signal in response to the command. The control circuit generates a second excitation signal sequence of the excitation interval followed by a second monitoring period to receive a second echo signal in response to the command. The control circuit outputs results via the port based on at least one of the first or second echo signals received.

A marine sonar display device comprises a display, a memory element, and a processing element. The display displays sonar images. The memory element stores sonar data. The processing element is configured to transmit a transmit electronic signal to a frequency steered sonar element which transmits an array of sonar beams into a body of water, each sonar beam transmitted in a different angular direction, receive a receive electronic signal from the frequency steered sonar element, the receive electronic signal including a plurality of frequency components, calculate an array of sonar data slices, one sonar data slice for each frequency component, generate an array of sonar image slices, one sonar image slice for each sonar data slice, and control the display to visually present the array of sonar image slices in near real time and a historical sequence of at least one sonar image slice.

A public area defense system, comprising a non-lethal reactive deterrence defense subsystem, an optical subsystem operably coupled to and in communication with the non-lethal reactive deterrence defense subsystem, and an acoustic subsystem operably coupled to and in communication with the non-lethal reactive deterrence defense subsystem. The public area defense system may further comprise a computer system in communication with each of the non-lethal reactive deterrence defense subsystem, the optical subsystem, and the acoustic subsystem, wherein each of the non-lethal reactive deterrence defense subsystem, the optical subsystem, and the acoustic subsystem are operable to interact with an actor

Beamforming method that allows a high speed and high accuracy beamforming with no approximate interpolations. This beamforming method includes step (a) that generates reception signals by receiving waves arrival from a measurement object; and step (b) that performs a beamforming with respect to the reception signals generated by step (a); and step (b) including without performing wavenumber matching including approximate interpolation processings with respect to the reception signals, and the reception signals are Fourier's transformed in the axial direction and the calculated Fourier's transform is multiplied to a complex exponential function expressed using a wavenumber of the wave and a carrier frequency to perform wavenumber matching in the lateral direction and further, the product is Fourier's transformed in the lateral direction and the calculated result is multiplied to a complex exponential function, from which an effect of the lateral wavenumber matching is removed, to perform wavenumber matching in the axial direction, by which an image signal is generated.

The present disclosure provides systems and methods associated with mode conversion for ultrasound and acoustic radiation devices. A mode converting structure (holographic metamaterial) is formed with a distribution of acoustic material properties selected to convert an acoustic pressure pattern from a first mode to a second mode to attain a target radiation pattern that is different from the input radiation pattern. A solution to a holographic equation provides a sufficiently accurate approximation of a distribution of acoustic material properties to form a mode converting device. One or more optimization algorithms can be used to improve the efficiency of the mode conversion and generation of the acoustic mode converter.

A filter coefficient vector generating unit (3) generates a filter coefficient vector used for forming directivity in a target direction by using beamforming, while suppressing the filter coefficient vector in such a way that the filter coefficient vector has a value equal to or less than a setting value. A beamforming unit (4) performs the beamforming on the basis of both observation signals acquired from a microphone array (2), and the filter coefficient vector generated by the filter coefficient vector generating unit (3), to form directivity in the target direction, and outputs a signal in which a sound having the formed directivity is emphasized.

A marine sonar display device comprises a display, a memory element, and a processing element. The display displays sonar images. The memory element stores sonar data. The processing element is configured to transmit a transmit electronic signal to a frequency steered sonar element which transmits an array of sonar beams into a body of water, each sonar beam transmitted in a different angular direction, receive a receive electronic signal from the frequency steered sonar element, the receive electronic signal including a plurality of frequency components, calculate an array of sonar data slices, one sonar data slice for each frequency component, generate an array of sonar image slices, one sonar image slice for each sonar data slice, and control the display to visually present the array of sonar image slices in near real time and a historical sequence of at least one sonar image slice.

A system for generating and injecting acoustic interference signals to mitigate undesired acoustic noise over a target zone. M pickup sensors pick up acoustic noise signals from one or more noise sources in real time and generate M noise signals, M>1. A beam forming network includes M acoustic beam forming modules to process the M noise signals respectively and generate N acoustic interference signals. N acoustic injectors condition, amplify and inject the N acoustic interference signals over the target zone, N>1. Each of the M acoustic beam forming modules includes a 1-to-N distribution network to transform a respective one of the M noise signals into N signals, and N finite-impulse-response filters to perform amplitude and phase weighting on the respective N signals and generate N intermediate signals which are combined respectively with corresponding intermediate signals generated by remaining M1 acoustic beam forming modules to generate the N acoustic interference signals.

A display apparatus includes a display panel configured to display a first image in a first direction and configured to display a second image in a second, different direction, a sound output unit including sound output modules to output a sound, and a sound focusing unit. The sound focusing unit is configured to receive first and second audio signals synchronized with video data signals of the first image and the second image, apply a direction focusing weight to the first and second audio signals, and to provide the sound output modules with a sound signal having the direction focusing weight applied thereto. Furthermore, the sound output unit is configured to receive the sound signal corresponding to the sound output modules, to output a first sound corresponding to the first image in the first direction, and to output a second sound corresponding to the second image in the second direction.