54results about How to "Reduce reverberation" patented technology

A piezoelectric micromachined ultrasonic transducer comprising a substrate and a first dielectric film formed on the substrate. An opening having a sidewall is formed through the substrate and first dielectric film. A bottom electrode is formed on the first dielectric film spanning the opening. A piezoelectric element is formed on the bottom electrode. A second dielectric film surrounds the piezoelectric element. A conformal insulating film is formed on the sidewall of the opening. A conformal conductive film is formed in contact with the bottom electrode and on the sidewall of the opening, wherein an open cavity is maintained in the opening. A top electrode is formed in contact with the piezoelectric element.

A method of correcting for pulse reverberations in ultrasound imaging using two-dimensional transducer arrays, and uses such reduction in element signals and beam signal before estimation of corrections for phase front aberrations of the ultrasound wave. The pulse reverberation is estimated by two transmit events, where the second event is determined by measurement and processing on measurement on echoes of the first event. In a second embodiment of the invention, the reverberation is estimated by a single transmit event, using two receive beams and processing on these. In a third embodiment of the invention the reverberation from very strong scatterers is reduced by adjustment of the active transmit aperture.

A system and method facilitating signal enhancement utilizing an adaptive filter is provided. The invention includes an adaptive filter that filters an input based upon a plurality of adaptive coefficients and modifies the adaptive coefficients based on a feedback output. A feedback component provides the feedback output based, at least in part, upon a non-linear function of the acoustic reverberation reduced output. Optionally, the system can further include a linear prediction (LP) analyzer and / or a LP synthesis filter. The system can enhance signal(s), for example, to improve the quality of speech that is acquired by a microphone by reducing reverberation. The system utilizes, at least in part, the principle that certain characteristics of reverberated speech are measurably different from corresponding characteristics of clean speech. The system can employ a filter technology (e.g., reverberation reducing) based on a non-linear function, for example, the kurtosis metric.

To provide a loudspeaker broadcasting system and a loudspeaker broadcasting apparatus which can perform a loudspeaker broadcasting of appropriate contents at each block without reducing sound clearness. Bi-directional speakers 1 which performs sound-reinforcement having high intelligibility, and fire detecting sensors 3 which detect fire occurrence in a tunnel 10a, 10b and send fire occurrence signals are placed in the tunnel 10a, 10b in the tunnel extending direction. In an emergency such as a fire, emergency broadcasting is performed through each bi-directional speaker 1 at each of the predetermined blocks 5 in the tunnel 10a, 10b. The emergency broadcasting is different in contents at each block, and it is alternately performed at the adjacent blocks 5. Further, the frequency components having a long reverberation time is removed from the loudspeaker broadcasting through the bi-directional speaker 1.

A system and process for finding the location of a sound source using direct approaches having weighting factors that mitigate the effect of both correlated and reverberation noise is presented. When more than two microphones are used, the traditional time-delay-of-arrival (TDOA) based sound source localization (SSL) approach involves two steps. The first step computes TDOA for each microphone pair, and the second step combines these estimates. This two-step process discards relevant information in the first step, thus degrading the SSL accuracy and robustness. In the present invention, direct, one-step, approaches are employed. Namely, a one-step TDOA SSL approach and a steered beam (SB) SSL approach are employed. Each of these approaches provides an accuracy and robustness not available with the traditional two-step approaches.

The present invention is a desktop speakerphone having a base-station and a detachable microphone pod. The base-station includes standard telephone components, as well as a wireless receiver and a housing for a detachable microphone pod. The detachable pod contains at least one microphone and a wireless transmitter. When the pod is attached to the base-station, and the conference mode of operation is activated, the pod microphone's audio signal goes directly to base-station audio circuitry via a wired connection. When the pod is detached and the conference mode activated, the pod microphone's audio signal now goes via the pod's wireless transmitter to the base-station's wireless receiver. This detached, wireless mode allows the microphone to be positioned anywhere in the room, thereby improving the quality of transmitted speech by increasing the speech-signal-to-room-noise ratio, and lessening the potential for room echo by reducing the acoustic coupling between base-station loudspeaker and pod microphone.

In an inner bottom surface of a case, a substantially oblong recess having a long axis and a short axis forms a vibration area. A piezoelectric element is bonded to the center of the recess. On the opposite sides of the vibration area, vibration suppression areas thicker than the vibration area are disposed. A side portion of the case is formed to be thin over the entire circumference thereof. A reinforcing member higher in rigidity than the case is bonded to upper portions of the vibration suppression areas. The reinforcing member has a bottom surface substantially equal to the shape of the vibration suppression areas, and has a predetermined height. A gap between the reinforcing member and an inner side surface of the case is also filled with a filling member.

A dereverberation apparatus includes a signal selecting unit which selects a sound signal to be used for dereverberation process from a plurality of sound signals, and a dereverberation processing unit which performs the dereverberation process for the selected sound signal.

The invention discloses a method and a device for ultrasonic image space compound imaging. The method comprises the following steps of: receiving ultrasonic echo signals with different deflection angles; performing image space compound imaging for the ultrasonic echo signals with different deflection angles; calculating the variance of the image data after the present compound imaging with the image data after the previous compound imaging, and then getting the absolute value, so as to obtain the variance image data, comparing the variance image data with a preset variance threshold, and judging whether the image data with a high motion attribute exists in the image data after the present compound imaging; and determining the output mode of the image data according to whether the image data with a high motion attribute exists in the image data after the present compound imaging. In the technical scheme of the invention, different image processing modes can be chosen according to the judged image motion attribute by judging the image data with a high motion attribute; and speckle noise, sound shadow and reverberation in an ultrasonic image can be effectively reduced, thus improving the definition of the image.