An external calibrating device (10) for a measurement device, which may be an acoustic camera. The calibrating device (10) includes a sound source (11) and a light source (12), which are preferably pointed to the same direction. This direction can be a horizontal direction, where the sources (11, 12) locate on the same vertical side surface of the calibrating device (10). An IR LED can be used as the light source (12). The measurement device may instruct a user how to place and align the measurement device during the calibration process. Guidance is given by instructions, volume range information, and focusing lines on the screen. When the instructions are fulfilled, the user may acknowledge the finished calibration process.

There is provided A method for producing an electrical impedance tomographic image of an acoustic field within a fluid, comprising the steps of: a) positioning a plurality of electrodes within a fluid; b) applying an electrical signal to each electrode within a first subset of electrodes, wherein the electrical signal applied to each electrode has a different carrier frequency and/or phase; c) measuring the electrical potential at each electrode within a second subset of electrodes; and d) processing the measured data to provide an acoustic map of the acoustic field at the required acoustic frequencies. There is also provided a system for producing an electrical impedance tomographic image of an acoustic field within a fluid using the method of any preceding claim, comprising a plurality of electrodes, a signal generator adapted to perform step (b), a device adapted to perform step (c), and a processor adapted to perform step (d).

An acoustic vector sensor and a method of detecting an acoustic vector are described. An object suspended in the fluid medium by a non-contact support structure. The object and the non-contact support structure are configured so that the object moves in response to any disturbance of the fluid by an acoustic wave; The non-contact support structure of the object comprises a plurality of solenoids that each produce a magnetic field in a fluid medium. A measurement measures movement of the object. A processing device determines an acoustic intensity vector of the acoustic wave based on the measured movement of the object.

Disclosed is an AI acoustic camera including an acoustic source localizing means unit of generating position-specific acoustic level data by determining a position of an acoustic source, an AI acoustic analysis unit of recognizing a type of acoustic source estimated as an abnormal acoustic source by extracting a regeneration time domain acoustic signal for the acoustic source with the determined position and AI-learning and recognizing an acoustic feature image of the extracted time domain acoustic signal, an object recognition unit of recognizing a type of object positioned in the acoustic source through image analysis of an area recognized as that the acoustic source is positioned, and a determination unit of determining the acoustic source as a true acoustic source when the type of acoustic source and the type of object have commonality.

An acoustic vector sensor (“AVS”) includes one or more sensitive elements arranged in an orthogonal configuration to provide high-sensitivity directional performance. The one more sensitive elements may be seismometers arranged in a pendulum-type configuration. The AVS further includes a hydrophone.

Methods of detecting and characterising a noise event are described, together with apparatus adapted to perform such methods. A method of characterising a noise event, involves locating microphones in an environment and generating a training event at a location in the environment as a reference for a noise event. A sound sample is recorded at each microphone and phase differences between the sound samples are used to establish a noise event signature for an event at that location. A noise event may subsequently be identified by taking sound samples from the microphones associated with the noise event and using phase differences between them to identify the noise event by matching against noise event signatures. A computing system adapted to perform such methods is also described.

A system for evaluating a characteristic of a portion of a building space, such as a room, may be provided. The system includes pairs of speakers and microphones associated with detection areas and forming audio multipath transmission channels. The system includes a controller communicatively coupled to the speakers and the microphones. The controller is configured to: (1) select detection areas; (2) activate the microphones corresponding to the pairs associated with the selected detection areas to capture one or more audio samples; (3) select speakers based on a baseline channel response matrix and the activated microphones; (4) transmit command signals to the selected speakers; (5) determine a characteristic channel response matrix based on the audio samples and audio signals corresponding to the command signals; and (6) evaluate the characteristic of the portion of the building space based on the characteristic channel response matrix and the baseline channel response matrix.

A vibration measurement sensor (3) adapted to measure the vibrations formed on a test object (O) with moving mechanical systems, at least one noise measurement sensor (4) adapted to measure sound intensity and/or particle velocity and/or sound pressure in at least one direction, i.e. on one axis, and a vibration and noise mapping system (1) that is adapted to control the vibration measurement sensor (3) and the noise measurement sensor (4), to provide the vibration and acoustic performance data of the test object (O) according to the data obtained from these units (3, 4) and to identify the areas on the test object (O) that are problematic or need to be studied further in order to improve vibration and acoustic performances thereof, and to control the operation of test objects (O) such as moving mechanical systems under different conditions.

A horizontal acoustic vector sensor system described herein includes a housing which has a gimbal assembly therein which is attached to a sensor assembly which has multiple pairs of seismometers that arranged orthogonally to one or more neighboring pairs of seismometers, along an approximately horizontal axis. The gimbal assembly with sensor assembly are enclosed within the housing by an endcap which includes an electronics assembly. The multiple pairs of seismometers are wired to the electronics assembly through a slip-ring which allows for movement of the gimbal assembly without entangling the wires. The horizontal acoustic vector sensor system further includes at least one omni-directional hydrophone integrated into the endcap.

Sounds arriving from outside of a mobile body are collected by a microphone disposed inside the mobile body. A sound collecting apparatus according to the present disclosure is attached to the mobile body. The sound collecting apparatus according to the present disclosure includes a microphone that is directly or indirectly in contact with an outer face member, which is a member forming an outer face of the mobile body, from an inner side of the mobile body and collects sounds propagating through the outer face member. In a case where the microphone has directivity, the microphone is disposed in a direction in which sounds propagating from the outer face of the outer face member to the inner side are collected. The outer face member is, for example, glass.