470 results about "Sound propagation" patented technology

Devices and methods are provided for assessing the condition of tissue, in particular to diagnose the location and stage of diseases such as emphysema. In one device or method according to the invention, sound is introduced into lung tissue. A portion of the sound is detected after it has passed through a portion of the lung. A sound-propagation parameter is determined by comparing a property of the introduced sound and a property of the detected sound. A region of examination of the tissue is identified, based in part on either a property of the component that introduces the sound or a property of the component that detects the sound. The condition of the tissue is assessed in the region of examination, based in part on the sound-propagation parameter.

The invention is related to a standoff comprising an acoustic coupling medium for use with an ultrasound transducer, comprising a first portion of tubular shape having a constant cross sectional area with an axis defining the direction of sound propagation and being adapted to be interfaced to the transducer, and a second portion of tapered shape being coaxial to the first portion. The second portion has a proximal end connected to the first, wherein the cross sectional area at a distal end of the second portion is smaller than the cross sectional area at the proximal end. The invention is further related to an envelope which is adapted to enclose the first and / or second portion of the standoff. The invention provides an improved acoustic standoff which is adapted for small and / or superficial structures.

A sound-capturing arrangement uses a set of directional microphones that lie approximately on a sphere having a diameter of 0.9 ms sound travel, which approximates the inter-aural time delay. Advantageously, one directional microphone points upward, one directional microphone points downward, and the odd number of microphones are arranged relatively evenly in the horizontal plane. On one embodiment, the signals from the microphones that point upward and downward are combined with the signals of the horizontal microphones before the signals of the horizontal microphones are transmitted or recorded.

An ultrasonic probe, including an ultrasonic element for transmitting and receiving ultrasonic waves; a sound window enclosing the ultrasonic element; and a sound propagation liquid charged in the sound window. A barrier layer capable of inhibiting the permeation of liquids and gases is provided on a wall surface of the sound window. As the barrier layer, at least one selected from a polyparaxylylene layer and a metal layer can be used.

The present invention relates to a sound rated floor system for inhibiting sound transmission between floors. The system includes a corrugated steel deck; a first layer of cementitious material or board or sheet applied over the corrugated steel deck; a sound insulation mat or board applied over the first layer; a second layer of cementitious material applied over the sound insulation mat or board. The floor system has an IIC rating of at least 25 and the corrugated steel deck provides at least 50 percent of the ultimate load carrying capacity under static and impact loading of the floor system with a floor deflection of at most 1 / 360 of the floor span.

An external inserting meatus of user is closed with an insert earphone device in use so that it is hard that external sound penetrates into the external inserting meatus; not only an internal sound propagation path but also an external sound propagation path are formed in an inserting body of the earphone device, and an active diaphragm is provided in the inserting body so as to make the external sound propagation path closed therewith and block the external auditory meatus from the external sound; the active diaphragm is formed from electroactive polymer layer sandwiched between electrodes, and the active diaphragm is deformed in the presence of voltage so as permit the user easily to control it.

An insert earphone device includes an electro-acoustic device, an inserting body, a sound tube connected between the electro-acoustic device and the inserting body and an active valve unit provided on the sound tube, the sound tube is formed with a sound propagation path open at both ends thereof to the electro-acoustic device and the inserting body and an external sound entrance open at both end thereof to environment and the sound propagation path, and the active valve unit is formed of electroactive polymer and responsive to voltage supplied through a cable so as to close and open the external sound entrance; when a user wishes to hear external sound, the user changes the polarity of voltage so that the active valve unit is deformed for conducting the environment to the sound propagation path, whereby the user hears the external sound without removing the earphone device from the ear.

The present invention provides a sound-transmitting membrane for a microphone, to be disposed to a sound-collecting opening of the microphone so as to allow sound to transmit through the membrane while preventing a foreign matter from entering into the microphone through the opening. This membrane for a microphone prevents the entry of a foreign matter, such as fine dust and water vapor, that is difficult for conventional sound-transmitting membranes to block, and ensures the microphone performance. This membrane for a microphone is composed of a nonporous film or a multilayer membrane including a nonporous film, has a surface density of 30 g / m2 or less, and has a sound transmission loss of less than 3 dB in a frequency range of 300 to 4000 Hz.

A clamp on apparatus 10,110 is provided that measures the speed of sound or acoustic disturbances propagating in a fluid or mixture having entrained gas / air to determine the gas volume fraction of the flow 12 propagating through a pipe 14. The apparatus includes an array of pressure sensors clamped onto the exterior of the pipe and disposed axially along the length of the pipe. The apparatus measures the speed of sound propagating through the fluid to determine the gas volume fraction of the mixture using adaptive array processing techniques to define an acoustic ridge in the k-ω plane. The slope of the acoustic ridge 61 defines the speed of sound propagating through the fluid in the pipe.

A time-based audio verification system used to verify the correct installation of an audio system in a vehicle is based on the principle that the distances between a pick-up microphone and each speaker within the vehicle are different. Sound travels at a constant rate, and the wave is measured that provides the time it takes the sound emanating from each speaker to travel to the microphone. Once it is determined where in the wave each speaker is located, the presence of each speaker in the vehicle can be determined. Additionally, the level of each speaker in the curve can be analyzed to determine individual speaker output quality.

An apparatus 10,110 is provided that measures the speed of sound or acoustic disturbances propagating in a fluid or mixture having entrained gas / air to determine the gas volume fraction of the flow 12 propagating through a pipe 14. The apparatus includes an array of pressure sensors disposed axially along the length of the pipe. The apparatus measures the speed of sound propagating through the fluid to determine the gas volume fraction of the mixture using adaptive array processing techniques to define an acoustic ridge in the k-ω plane. The slope of the acoustic ridge 61 defines the speed of sound propagating through the fluid in the pipe.

Acoustic waves exhibit a a streaming force that pushes objects along the direction of sound propagation. Precise motions require well-focused beams. The technique of time-reversal acoustics (TRA) overcomes beam distortions introduced by propagation along irregular paths to focus sound without knowledge of the medium properties. TRA requires a small receiver to be placed at a point of desired focus. The invention disclosed refines TRA by introducing data matching schemes to extend the points of focus beyond the location points of the receivers. With as few as two receivers, a large region can be manipulated with well-focused acoustic beams and with no receiver at a desired point of focus. Applications are described in drug delivery in medicine; environmental fluid contaminant control; and in oil exploration, for retrieving oil stuck in underground pockets.

An apparatus for processing passive acoustic signals received on a horizontal line array that were either emitted from an underwater object or echo returned from an object, is proposed to track the motion (bearing change and range change) of an object (target) relative to the receiver horizontal line array. Adaptive array processing for a moving object is biased for a moving source when the number of data samples is limited by the stationariness condition. Motion compensation can be carried out in the beam domain by beam shifting for a bearing changing object and frequency shifting for a range changing object. The method includes receiving acoustic signals from the target, determining the beam covariance matrices, determining the target bearing rate and range rate, processing the beam covariance matrices by compensating for the target motion, and producing a beam power plot versus time. Interference signal is suppressed when the interference source does not have the same motion (bearing and range rate) as the target. The method does not need detailed environmental acoustic information of the sound channel normally required to model the sound propagation.

The invention provides a method for carrying out ultrasonic inspection on residual stress of an aluminium alloy pre-stretching board by water immersion, belonging to the field of non-destructive inspection. The method comprises the following steps of preparing a reference block; carrying out measurement and calibration; measuring the residual stress. In the method, the water immersion method is adopted, and the temperatures in stress calibration and stress measurement processes can be ensured to be consistent by controlling the water temperature not to be changed, thus eliminating the effects of temperature difference on the ultrasonic wave speed and eliminating temperature errors; besides, an automatic scanning frame is adopted instead of manual scanning, so that the distance between a probe and the surface of a material to be measured in the measurement process can be ensured not to be changed, thus eliminating the effects of coupling condition difference on sound propagation time and eliminating the coupling errors. The method is beneficial to non-destructive evaluation of the near surface residual stress of the aluminium alloy pre-stretching board.

The invention discloses a three-dimensional structure sound source radiation sound field forecast method under the shallow sea channel and belongs to the sound source radiation sound field forecast field. The method is characterized in that firstly, a structure sound radiation multi-physical field coupling model under the shallow sea channel is established, the sea sound propagation theory is selected according to analysis frequency range, calculation distance and shallow sea environment factors to establish a two-dimensional axisymmetric channel transmission function G, through orientation coupling solution development, a channel three-dimensional sound field transmission function is acquired, secondly, the shallow sea channel multi-boundary sound field coupling calculation theory is employed to establish a multi-physical field coupling model, a structure sound source surface speed U under the shallow sea channel under the action of multi-boundary influence is acquired through calculation, and lastly, the Fourier wave superposition method theory is utilized to forecast the sound field information P of a structure sound source at any field point under the channel is forecasted. Themethod is advantaged in that multiple bottleneck problems of high computational complexity, multiple coupling physical fields and complex channel environments existing during researching three-dimensional elastic structure sound source radiation sound field characteristics under the complex shallow sea channel in the prior art are effectively solved.

A method for the determining ultrasonic sound propagation speed and wall thickness of a tubular object. Time-domain and frequency-domain analyses are used, where the latter can determine acoustic dispersion if the specimen is made up of a dispersive material. Data is sensed from a series of transmitted ultrasonic waves, some of which are reflected. The data can be used to calculate speed of sound in the tube, as well as wall thickness. Inherent in the data is the speed of the ultrasonic wave; accordingly, correction for temperature variations in the tube is not required. The calculations based on measured speed of sound quantities produces more accurate results than in calculations where the speed of sound in the specimen is assumed.

The invention provides a method for the precise calibration of the absolute position of a deep sea underwater transponder, which comprises the following steps of: 1, measuring a sound propagation delay by using the request and response between a ship transducer and a seabed transponder at multiple measuring points; 2, measuring an absolute geodetic coordinate of each measuring point by using a GPS; 3, measuring sound velocity distribution on site in a sea area anchored by the seabed transponder; 4, calculating an initial value of the absolute position of the underwater transponder according to an average sound velocity and a transducer position calibration equation; 5, calculating a horizontal distance from each measuring point to the underwater transponder according to the initial value of the absolute position of the underwater transponder, the absolute geodetic coordinates of the measuring points, the sound propagation delay and the sound velocity distribution; 6, calculating the horizontal coordinate of the underwater transponder according to the position of each measuring point and the horizontal distance, obtained by the step 5, from each measuring point to the underwater transponder; and 7, calculating a depth coordinate of the underwater transponder according to the position of each measuring point, the horizontal coordinate, obtained by the step 6, of the underwater transponder, the sound propagation delay and the sound velocity distribution. The method for the precise calibration of the absolute position of the deep sea underwater transponder can greatly improve working efficiency and enjoys a more obvious advantage under a deep sea condition.

A loudspeaker enclosure is arranged to support at least one electromagnetic loudspeaker driver generating both front and back acoustic waves. The front of the speaker is substantially planar and the driver is mounted in an opening in the front of the enclosure to radiate forwardly. The driver's back wave communicates through a passage adapted to function as an impedance-matched transmission line cavity having a length that is, preferably, three times the driver cone's diameter, and having one or more ports terminating in openings defined in a plane that is, preferably, substantially perpendicular to the enclosure's planar front. The port or ports have a cross sectional area of, preferably 0.707 to 1.414 times the operative area of the driver cone, thereby giving a highly efficient means of sound propagation.

The purpose of this invention is to provide a support device for a resonator that can support the resonator at an optional location, can let the resonator vibrate with a specified vibration consistently, and can apply an ultrasonic vibration to objects efficiently. By inserting first clamping means and second clamping means, which comprise supporting member at least at each contacting portion, into first portion-to-be-supported and second portion-to-be-supported of resonator, the resonator is supported. As substances of the supporting member, substances that have a logarithmic decrement higher than 0.01 and lower than 1.0 and / or a sound propagation speed of more than 5900 m / s are suitable.

The invention discloses an acoustic flow measurement device and a method thereof. The acoustic flow measurement device is adopted between observation stations for sending sound waves to the opposite side simultaneously, then receiving sound waves transmitted by the opposite side, the bidirectional propagation time of the sound waves between the two observation stations is obtained by calculating; the difference and the sum of the acoustic signals bidirectional propagation time are used for reversing the mean velocity and the average temperature between observation stations. The invention can carry on the vertical sample based on sound propagation multi-path effect by only using a pair of sound-source-receiver; as the ocean interior images can be obtained by observing the external measurement of the sea; compared with the traditional method, the synchronous measurement with the large-scale and long time between two points by using a pair of instruments can be realized; the collection performance of the sound propagation can obtain ocean environment parameters with the vast scale in space and the average time which can not be obtained by the traditional point sensor; the method solves the problem that the observing is affected by shipping and fisheries activity.

A system and method for quickly modeling the ideal acoustic sound propagation in a body of water based on current SVP data and the position of the sound source, comprising the steps of: obtaining SVP data for the body of water; determining a depth of a sound source within the body of water; selecting a first ray angle originating from the sound source; calculating a first ray trace for the first ray angle using only the SVP data as environmental inputs; repeating the selecting and calculating steps for second-nth ray angles to calculate second-nth ray traces for the second-nth ray angles; and plotting the first-nth ray traces to create a ray trace plot for the body of water relative to the depth of the sound source.

An inserting type earphone device is broken down into a signal-to-sound converter, an ear pad to be inserted into an acoustic meatus of user, a sound tube provided between the signal-to-sound converter and the ear pad and a switching mechanism provided in association with the sound tube and ear pad, and a sound hole, which is formed in the sound tube for connecting a sound propagation hole to the outside, is open to and closed with the switching mechanism; the switching mechanism makes the sound hole open and closed through rotation thereof around the sound tube so that the ear pad is not inclined in the acoustic meatus during the rotation, whereby the ear pad is not dropped off from the acoustic meatus.

Methods for real-time, continuous measurements of the composition and other properties of individual phases of petroleum, water and gas mixtures during the oil production process, without requiring test separators, test lines, with associated valving and instrumentation, are described. Embodiments of the present invention direct ultrasonic sound transmission through a flowing multiphase fluid in three frequency ranges: low frequencies, gas bubble resonance frequencies, and high frequencies, wherein certain sound propagation measurements, including sound speed, sound attenuation and sound scattering, are made in one or more of the three separate frequency regions, from which the multiphase composition and other properties are extracted without having to separate the multiphase fluid or the gas from the flowing stream.

In fuel reservoir injection systems also known as common rail fuel-injection systems (1) for motor vehicles the problem exists that for a defined quantity of fuel that is about to be injected it is necessary to take into account not only the predominant pressure of the fuel but also its temperature. It is difficult to install and use a temperature sensor to detect the fuel temperature. The invention therefore proposes a method and a device for determining the temperature (T) from the pressure (P) measured by the pressure sensor (4) and the sound-propagation velocity (V) of a shock wave triggered at the moment of injection.

An external inserting meatus of user is closed with an insert earphone device in use so that it is hard that external sound penetrates into the external inserting meatus; not only an internal sound propagation path but also an external sound propagation path are formed in an inserting body of the earphone device, and an active diaphragm is provided in the inserting body so as to make the external sound propagation path closed therewith and block the external auditory meatus from the external sound; the active diaphragm is formed from electroactive polymer layer sandwiched between electrodes, and the active diaphragm is deformed in the presence of voltage so as permit the user easily to control it.

Active acoustic velocity and pyrometry-based gas flow velocity and temperature measurement, such as for monitoring of gas turbine combustors, including industrial gas turbine (IGT) combustors is incorporated into the combustion monitoring and control system by addition of an acoustic transmitter or acoustic transceiver that transmits a sound wave in a line-of-sight with a plurality of acoustic sensors, such as dynamic pressure sensors. For velocity measurement, sound transmission time-of-flight that is directed generally along the gas flow path is measured by the controller and correlated with gas flow velocity along the line-of-sight. Similarly, sound transmission time-of-flight is correlated with temperature along the line-of-sight. Path(s) of acoustic transmission serve as velocity or velocity / absolute temperature measurement. In an integrated thermoacoustic pressure-based sensor and monitoring / control system embodiment, the controller correlates velocity and, if desired, absolute active path temperatures with acoustic transmission and time-of-flight analysis techniques.

In a component operating with acoustic waves, a GDE layer is provided in close mechanical contact with a piezoelectric excitation layer which can significantly change their rigidity under a mechanical warping and the sound propagation speed. The degree of the material expansion or, respectively, compression can be adjusted by applying a voltage to two control voltage electrodes and a piezoelectric tuning layer.

The invention discloses a system and method for measuring distribution of strong focused ultrasound nonlinearity sound fields, and belongs to the technical field of ultrasound field measurement. The method comprises the steps that firstly, a distribution curve of the sound pressure in the axial direction of a spherical shell energy converter and a distribution curve of the sound pressure in the radial direction of a focal plane of the spherical shell energy converter are obtained; secondly, the sound pressure distribution curve in the axial direction of the spherical shell energy converter and the sound pressure distribution curve in the radial direction of the focal plane are calculated according to the Rayleigh integral, and the calculating result is compared with the measuring result to obtain a valid parameter; thirdly, the valid parameter is substituted into a nonlinearity sound propagation model to calculate R21, the P0 values are changed, R21 corresponding to different P0 values is calculated, and then the relation curve of R21 and P0 is obtained; fourthly, excitation is exerted on the spherical shell energy converter, the focus waveform is measured to be calculated to obtain R21', and P0' corresponding to R21' is obtained through interpolation; fifthly, P0' is substituted into the nonlinearity sound propagation model, and then the distribution of the nonlinearity sound fields is obtained. The system and method effectively solve the problem that the bandwidth of a hydrophone is insufficient when the hydrophone is used for measuring the nonlinearity sound fields, the relative value R21 serves as a judgment basis, and measuring hidden danger caused by not high sensitivity of the hydrophone is eliminated.