Abstract: Methods and systems are disclosed for determining pose information for at least one of a transmitter and receiver, both of which comprise ultrasonic transducers. A relative position is determined between the transmitter and the receiver and an orientation for at least is also determined. After obtaining field of view data for at least one of the transmitter and receiver, a field of view between them is determined, based at least in part on the field of view data, the determined relative position and the determined orientation. The pose information is then determined by weighting measurements of an ultrasonic signal emitted by the transmitter and received by the receiver based at least in part on the determined field of view relationship.

Abstract: There is disclosed an acoustic transducer for communications within an operational bandwidth, the transducer comprising: A signal generator for generating a signal at a centre-frequency within the operational bandwidth; A piezoelectric element having a dielectric constant that varies with temperature; A driving electrode at the surface of the piezoelectric element; A matching network, having a natural frequency at a given temperature, and operable to transfer the signal from the signal generator to the piezoelectric element whilst mitigating electrical loss, the matching network being connected to the driving electrode; Wherein the matching network comprises a temperature compensating capacitor connected in parallel with the piezoelectric element, the temperature compensating capacitor being for counteracting temperature-induced changes to the dielectric constant of the piezoelectric element such that the electrical natural frequency of the transducer is substantially constant over a range of temperatures.

Abstract: A method including receiving an audio scene including at least one source captured using at least one near field microphone and at least one far field microphone. The method includes determining at least one room-impulse-response (RIR) associated with the audio scene based on the at least one near field microphone and the at least one far field microphone, accessing a predetermined scene geometry corresponding to the audio scene, and identifying a best matching geometry to the predetermined scene geometry in a scene geometry database. The method also includes performing RIR comparison based on the at least one RIR and at least one geometric RIR associated with the best matching geometry, and rendering a volumetric audio scene experience based on a result of the RIR comparison.

Abstract: A sound system design/simulation system provides a more realistic simulation of an existing venue by matching a measured reverberation characteristic of the existing venue and adjusting one or more acoustic parameters characterizing the model such that a predicted reverberation characteristic substantially matches the measured reverberation characteristic.

Abstract: A test battery method and system for use in assessing auditory function (e.g., the screening or diagnosis of impairments, fitting of hearing aids, etc.) is provided which performs one or more auditory tests including, for example, an acoustic reflectance test. Such an acoustic reflectance test may be a reflectance tympanometry test that includes a feedback system to control static pressure in the ear canal. Such acoustic reflectance tests may be used alone or in combination with one or more other auditory tests. Further, for example, such a battery of tests may include middle-ear muscle reflex tests in combination with one or more other auditory or hearing tests.

Abstract: A method of modeling a room impulse response according to an embodiment of the invention includes receiving a sound pressure signal that is obtained by a microphone when an impulse-type sound source is excited and detecting a room impulse response; determining boundaries between a plurality of intervals of the room impulse response such that the room impulse response is divided into the plurality of intervals on a time domain; and modeling the room impulse response for each of the plurality of divided intervals using at least two different modeling schemes.

Abstract: A test battery method and system (10, 100, 200, 225) for use in assessing auditory function (e.g., the screening or diagnosis of impairments, fitting of hearing aids, etc.) is provided which performs one or more auditory tests including, for example, an acoustic reflectance test. Such an acoustic reflectance test may be a reflectance tympanometry test that includes a feedback system to control (426) static pressure in the ear canal. Such acoustic reflectance tests may be used alone or in combination with one or more other auditory tests. Further, for example, such a battery of tests may include middle-ear muscle reflex tests in combination with one or more other auditory or hearing tests.

Abstract: A method for generating and checking a spatio-temporal field distribution having predefined characteristics such as one or more directions of propagation, a high level of field intensity and a polarization in a reverberant chamber. To do this, two separate networks of transducers are provided so as to estimate a transfer function between these two networks and to determine excitation signals using the principle of temporal return. The excitation signals are used to generate the spatio-temporal field according to the predefined characteristics.

Abstract: Methods of acoustic imaging provide images with reduced reverberation noise and images of nonlinear scattering and propagation parameters of the object, and estimation methods of corrections for wave front aberrations produced by spatial variations in the acoustic propagation velocity. The methods are based on processing of the received signal from transmitted dual frequency band acoustic pulse complexes with overlapping high and low frequency pulses. The high frequency pulse is used for the image reconstruction and the low frequency pulse is used to manipulate the nonlinear scattering and/or propagation properties of the high frequency pulse. Through filtering in the pulse number coordinate and corrections for nonlinear propagation delays and optionally also amplitudes, a linear back scattering signal with suppressed pulse reverberation noise, a nonlinear back scattering signal, and quantitative nonlinear forward propagation and scattering parameters are extracted.

Abstract: A measurement systems that reduces spurious artifacts in reflected signals by generating and employing an improved maximum length sequence. Accurate acoustic measurements with both high SNR and low spurious artifacts are made possible by generating Wide MLS (WMLS) which modifies a base MLS by replacing each value with a sequence that includes the value and one or more additional values, where typically the replaced values have opposing polarities and, the additional signals have intermediate values. An exemplary intermediate values can be approximately zero value.

Abstract: The present invention relates to a method and apparatus for non-invasive monitoring of brain density variations. At least two ultrasonic pulses having different frequencies are provided into the brain for transmission therethrough. The reflected ultrasonic pulses are then sensed and the sensed signal data are then processed for determining at least two phase differences between the phases of the at least two reflected ultrasonic pulses and the phases of the at least two provided ultrasonic pulses. A phase of at least a beat frequency is determined in dependence upon the at least two phase differences. Data indicative of a brain density variation are determined based on the at least two phase differences and the at least a beat frequency.

Abstract: An enclosed test stand may be enclosed by at least two reverberant boundary surfaces. Two of said at least two reverberant boundary surfaces may abut against each other to form an edge. A first linear array of microphones may be configured to detect acoustical signals of a sound field. The linear array of microphones may be arranged along the edge. An evaluating unit may be coupled to the linear array of microphones. The evaluating unit may be configured to locate sound sources of the sound field.

Abstract: An acoustic inspection apparatus and its transport device are disclosed. The acoustic inspection apparatus includes an anechoic chamber and a transport device. The anechoic chamber defines an entrance. The transport device includes a support frame, guiding rails, sliding blocks, a motor, and a multiple holder. The guiding rails are mounted on the support frame. The sliding blocks are fitted on the guiding rails. The motor drives the sliding blocks moving along the lengthwise direction of the guiding rails. The multiple holder is connected with the sliding blocks and at least includes an acoustical anechoic chamber cover and a holding platform configured for supporting a sound device that to be inspected. The acoustic inspection apparatus can be used in product line to inspect sound devices.

Abstract: A device for detecting a resonant frequency comprises a sound source, a switch, a mixer, and a sound meter. The switch and mixer are capable of switching between a first state in which the switch and mixer output a measurement signal and a second state in which the switch and mixer output a synthesized signal containing the measurement signal and the signal output from a microphone. The device detects the resonant frequency based on comparison between the first amplitude frequency characteristic measured in the first state and the second amplitude frequency characteristic measured in the second state.

Abstract: In order to measure a sound characteristic in a sound space, measurement sound is outputted to the sound space. Measurement sound data of a predetermined time period, which is prepared in advance, is divided into plural block periods, and plural block sound data are generated. A reproduction process of reproducing the plural block sound data in the order forming the measurement sound data is executed plural times by shifting the block sound data reproduced first by one for each time. Thereby, the measurement sound is outputted. When the above reproduction process is executed plural times, detected sound data corresponding to the block sound data reproduced at the identical reproduction order for each time are operated, and a sound characteristic is determined. Thereby, it becomes possible to measure the sound characteristic in the period shorter than the measurement sound data of the predetermined time period.

Abstract: An ultrasonic sensor includes a piezoelectric vibrator, a reverberation measuring device and a compensating device. The piezoelectric vibrator vibrates to transmit an ultrasonic wave, receives a reflected wave of the transmitted ultrasonic wave and produces an output signal corresponding to vibration of the piezoelectric vibrator. The reverberation measuring device measures a reverberation period of the piezoelectric vibrator from the output signal. The compensating device compensates for an operation characteristic of the piezoelectric vibrator in accordance with the measured reverberation period. Thus, the ultrasonic sensor can decrease a reverberation period, which may cause reduction in detection accuracy and impossibility of detection of an obstacle at a short distance.

Abstract: A sound field measuring apparatus has: an exponential pulse generator 11 which outputs a pulse signal to speakers 4a, 4b, . . . ; a microphone 6 which is disposed in an acoustic space 5 where the speakers 4a, 4b, . . . are disposed, and which detects a pulse signal output from each of the speakers 4a, 4b, . . . ; and a calculation section 15 which detects a time when the signal detected by the microphone 6 exceeds a predetermined threshold. The calculation section 15 calculates a time period from a time when the pulse signal is generated by the exponential pulse generator 11 to the time when the signal exceeds the predetermined threshold.

Abstract: The present invention finds the acoustic impedance of the drilling fluid using reflections from a precise metal disk, and therefrom the density of the drilling fluid. Because the reverberation characteristics of an acoustic wave depend in part on the acoustic wave shape, the first reflection from the metal disk may be used to calibrate the measurement. A method for determining a borehole fluid property is disclosed that includes (i) generating an acoustic signal within a borehole fluid, (ii) receiving reflections of the acoustic signal from the fluid, and (iii) analyzing a reverberation portion of the acoustic signal to determine the property. The analyzing of the reverberation portion may include obtaining a theoretical reverberation signal and relating the measured reverberation signal with the theoretical reverberation signal to determine the borehole fluid property.

Abstract: An obstacle detecting system for vehicles has an ultrasonic vibrator having a vibration plate and mounted on a vehicle to transmit and receive an ultrasonic wave. An obstacle is detected in response to an output signal of the ultrasonic vibrator. When the temperature around the ultrasonic vibrator is below a predetermined temperature corresponding to snowfall, the system calculates a ratio of a period of reverberating vibration of the ultrasonic vibrator relative to a predetermined time period following an ultrasonic wave transmission, and determines accumulation of snow when the calculated ratio exceeds a predetermined time ratio. The system notifies an abnormality of the ultrasonic vibrator arising from the accumulation of snow.

Abstract: Disclosed is a noise source visualizing system used in a wind tunnel test to measure generated sounds, the system comprising an acoustic mirror for converging sound waves of sounds generated on a surface of a vehicle during a wind tunnel test; a microphone measuring the converged sound waves; an image-photographing unit photographing locations on the vehicle at which the sounds are generated; a first display unit displaying the sounds measured by the microphone as colors that vary according to characteristics of the sounds; a movable traverse to which the acoustic mirror is connected for enabling the acoustic mirror to collect the sounds; a workstation for analyzing the converged sound waves measured by the microphone, the images photographed by the image-photographing unit, and the signals displayed through first display unit; and a second display unit overlapping then displaying image signals photographed by the image-photographing unit and the colors displayed on the first display unit.

Abstract: The spectral content of a transient stress wave event occuring on a plate-like structure is determined by locating a transducer on the surface of the structure at a position remote from the location of the transient stress wave event. Lamb waves resulting from and characteristic of the transient stress wave event propogate through the plate-like structure in a dispersive manner to be intercepted by the transducer. Analysis of the transducer output enables the spectral content of the transient stress wave event to be realized.

Abstract: A method of detecting inadequately supported sections or overloaded points in a pipeline including the steps of traversing the interior of the pipeline with an instrumentation pig, sequentially striking or vibrating the wall of the pipeline by means carried by the pig to introduce vibratory signals into the pipeline, receiving said signals from within the pipeline by listening to the sounds generated as a consequence of the striking of the interior wall, and detecting preselected characteristics of received sound which are indicative of unsupported sections or of points of load and stress concentration in the pipeline.

Abstract: A hammer-type device is driven by a cam and spring arrangement in reciprocating motion to strike a moving train wheel for producing vibrations therein which are used to detect defects in the wheel.

Abstract: A device for measuring reverberation characteristics in a reverberation room by a digital squaring and integrating computation process. According to the invention, only a part of digital data of a large word length obtained by squaring and integrating a reverberation signal is selected out for computing the reverberation characteristics in accordance with a measuring environment such as integration time and duration of a test pulse. By this arrangement, circuitry for computing the reverberation characteristics can be made compact and time required for computing can be shortened without sacrificing the accuracy of measurement. Further, according to the invention, the level of an input signal can be computed and displayed by computing intermediate squared and integrated data at a certain time interval and adding this data with compensation data corresponding to a frequency band width of the input signal.

Abstract: A device for measuring acoustic reverberation time incorporates a transmission unit and a reception unit combined together into one assembly. Both units share a single series of filters, one of which filters is inserted into a signal path for the transmission unit and for the reception unit. The device serves to measure accurately the acoustic reverberation time of acoustic spaces such as recording rooms, sound studios and the like.