An augmented reality-based acoustic analysis method includes identifying structural elements of a space and determining structural parameters of the structural elements and a structural parameter of the space. The method further includes displaying, by an augmented reality (AR) device, a virtual lighting fixture model on a viewport of the AR device, where the virtual lighting fixture model is overlaid on a real-time image of the space. The method also includes determining, by the AR device, a sound reverberation time of the space based on at least a sound absorption parameter associated with the virtual lighting fixture model and a sound absorption parameter of the space determined based on the structural parameters of the structural elements and the structural parameter of the space.

An augmented reality-based acoustic analysis method includes identifying structural elements of a space and determining structural parameters of the structural elements and a structural parameter of the space. The method further includes displaying, by an augmented reality (AR) device, a virtual lighting fixture model on a viewport of the AR device, where the virtual lighting fixture model is overlaid on a real-time image of the space. The method also includes determining, by the AR device, a sound reverberation time of the space based on at least a sound absorption parameter associated with the virtual lighting fixture model and a sound absorption parameter of the space determined based on the structural parameters of the structural elements and the structural parameter of the space.

Acoustic pickup beams (sound beams) can be formed in a physical environment from a plurality of microphone signals. Each of the sound beams can measure acoustic energy in a direction of the respective sound beam. Directional decay of the acoustic energy measured through each of the sound beams is determined. Room surface acoustic properties of the physical environment are determined based on mapping the directional decay of the acoustic energy to the physical environment. Other aspects are described and claimed.

Acoustic pickup beams (sound beams) can be formed in a physical environment from a plurality of microphone signals. Each of the sound beams can measure acoustic energy in a direction of the respective sound beam. Directional decay of the acoustic energy measured through each of the sound beams is determined. Room surface acoustic properties of the physical environment are determined based on mapping the directional decay of the acoustic energy to the physical environment. Other aspects are described and claimed.

In accordance with an example aspect of the present invention, an apparatus is provided, the apparatus comprising at least one processing core, at least one memory including computer program code, the at least one memory and the computer program code being configured to, with the at least one processing core, cause the apparatus at least to derive, from first digital information describing a system impulse response caused by a loudspeaker to a first location in a first room, second digital information describing a cancelling impulse response, determine, for samples comprised in the second digital information, at least one of a delay value describing how much the samples are to be shifted in time and a gain factor describing how much the samples' magnitude is to be adjusted, so that an energy associated with a sum of the system impulse response and the cancelling impulse response is reduced, and employ the determined at least one of the delay value and the gain factor to generate a cancelling signal, and to add the cancelling signal to a signal provided to the loudspeaker.

A sound velocity sensor for underwater use has an acoustic transmitter and receiver, a path length portion defining an acoustic path and positioned such that a generated acoustic signal propagates along the acoustic path from the acoustic transmitter to the receiver, a temperature sensor in direct contact with the path length portion, and a controller communicatively coupled to these components. The controller is configured to generate the acoustic signal using the acoustic transmitter, determine a transit time of the acoustic signal from the acoustic transmitter to the acoustic receiver, determine a temperature of the path length portion using the temperature sensor, and determine the velocity of the acoustic signal from the transit time and a length of the acoustic path. Determining the velocity includes compensating for a temperature-related change in the length of the acoustic path using the temperature of the path length portion.

A part (120) may be subjected to both a resonance inspection and a surface vibration inspection. Various protocols (230; 240; 250; 280; 260) are disclosed as to how the results of one or more of these inspections may be used to evaluate the part (120).

A transmitting piezoelectric element and receiving piezoelectric elements and are arranged on a vibrating plate opposed to each opening of openings of a piezoelectric sensor, and, when an external force is applied in a vertical direction with respect to the vibrating plate opposed to the openings, a region which has a maximum principal stress which is a maximum value of the stress of the vibrating plate is a first region, and a region which has a minimum principal stress which is a minimum value of the stress of the vibrating plate is a second region, the receiving piezoelectric elements and are arranged in the first region and the transmitting piezoelectric element is arranged in the second region.

One or more embodiments set forth an audio presence detection system, with a memory that includes an acoustic presence detection application, and a processor that executes the acoustic presence detection application. The audio presence detection system receives a first input signal associated with a first speaker, and receives a second input signal associated with a first microphone. The audio presence detection system generates, via an adaptive filter, a first estimation signal based on at least the first input signal and an impulse response associated with a room related to the first speaker and the first microphone. The audio presence detection system computes a first error signal based on the second input signal and the first estimation signal. The audio presence detection system determines that an object is present within a space based on a magnitude associated with the first error signal relative to a first threshold level.

One or more embodiments set forth an audio presence detection system, with a memory that includes an acoustic presence detection application, and a processor that executes the acoustic presence detection application. The audio presence detection system receives a first input signal associated with a first speaker, and receives a second input signal associated with a first microphone. The audio presence detection system generates, via an adaptive filter, a first estimation signal based on at least the first input signal and an impulse response associated with a room related to the first speaker and the first microphone. The audio presence detection system computes a first error signal based on the second input signal and the first estimation signal. The audio presence detection system determines that an object is present within a space based on a magnitude associated with the first error signal relative to a first threshold level.