53results 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.

The present invention is directed to a telephone equipped with multiple microphones that provides improved performance during operation of the telephone in a speaker-phone mode. For example, the multiple microphones can be used to improve voice activity detection, which in turn, can improve echo cancellation. In addition, the multiple microphones can be configured as an adaptive microphone array and used to reduce the effects of (i) room reverberation, when a near-end user is speaking, and/or (ii) acoustic echo, when a far-end user is speaking.

A system and method facilitating signal enhancement utilizing mixture models is provided. The invention includes a signal enhancement adaptive system having a speech model, a noise model and a plurality of adaptive filter parameters. The signal enhancement adaptive system employs probabilistic modeling to perform signal enhancement of a plurality of windowed frequency transformed input signals received, for example, for an array of microphones. The signal enhancement adaptive system incorporates information about the statistical structure of speech signals. The signal enhancement adaptive system can be embedded in an overall enhancement system which also includes components of signal windowing and frequency transformation.

The invention relates to a whole image sound barrier for an urban quick lane and a tunnel portal. The sound barrier is characterized by consisting of gate-type arc steel arch racks arranged in the upper space of a pavement, and a sound barrier main body framework consisting of rigid tie rods for connecting the adjacent arch racks and cross supporting rods, wherein purlines are arranged on the main body framework; and meanwhile, the purlines arranged on the main body framework are used as supports, anti-collision wall contact faces are formed symmetrically on the left and right sides along the central axis of the sound barrier till the pavement, and a sound absorber, a ventilated exhaust part, a sound absorber, a lighting part, a sound absorber and a lighting part are arranged at intervals, so that a full-closed for semi-closed whole image sound barrier structure capable of totally isolating direct sound is formed for a road. The whole image sound barrier for the urban main road can effectively reduce the traffic noise of the urban main road, effectively reduce the reverberation in a sound barrier area and ensure the safety and the comfort degree of a road user, and is a sound barrier suitable for a building dense area nearby the urban main road.

The invention relates to an acoustic positioning system, in particular to an acoustic positioning system of a shallow sea wave detector for secondary positioning of a seabed wave detector in shallow sea petroleum earthquake exploitation. The system mainly comprises a carrier-borne part and a seabed part, wherein the carrier-borne part consists of processing software, a host machine and a receiving and transmitting combined transducer; and the seabed part consists of a plurality of seabed transponders. Because the technology for manufacturing the receiving and transmitting combined transducer is adopted, the designed source level and the sensitivity meet the positioning requirement of a complex exploitation area of the shallow sea; and the underwater working posture of the transducer is kept and the turbulence and reverberation are reduced by designing streamline turning vanes. Therefore, the system meets the requirements of high recovery ratio and high positioning efficiency of secondary positioning of a secondary positioning earthquake exploitation water detector in the Bohai Bay area.

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.

The present invention provides a time-reversal emission focusing reverse beam forming method based on high frequency time-reversal array. The beam forming method uses high frequency time-reversal array. A sound wave is emitted to irradiate the object and an echo signal from the object is received. The received echo signal is turned on time and emitted back. The time-reversal signal can focus at the object place, which performs as time waveform compression and space-focusing. An enhanced object echo signal is received again to form a receiving focusing beam. The present invention provides the time-reversal emission focusing reverse beam forming method based on the high frequency time-reversal array which uses a high frequency time-reversal mirror which is suitable for shallow water acoustic fields, reduces the reverberation and improves the detection ability to shallow water.

The present technology provides robust, high quality dereverberation of an acoustic signal which can overcome or substantially alleviate the problems associated with the diverse and dynamic nature of the surrounding acoustic environment. The present technology utilizes acoustic signals received from a plurality of microphones to carry out a multi-faceted analysis which accurately identifies reverberation based on the correlation between the acoustic signals. Due to the spatial distance between the microphones and the variation in reflection paths present in the surrounding acoustic environment, the correlation between the acoustic signals can be used to accurately determine whether portions of one or more of the acoustic signals contain desired speech or undesired reverberation. These correlation characteristics are then used to generate signal modifications applied to one or more of the received acoustic signals to preserve speech and reduce reverberation.

The invention provides a loudspeaker array sound reinforcement system for inhibiting howling. The system comprises an input signal processing module (1), a filter module (2), a multichannel power amplifier (3) and a loudspeaker array (4); the filter module (2) comprises a parameter setting unit (201), a filter group generation unit (202) and a filter group processing unit (203); the filter group generation unit (202) is used for calculating convolution matrixes Hm and Hn formed by time domain impulse response at each control point of the loudspeaker array (4) according to parameters set by the parameter setting unit (201); calculating matrixes Rb and Rd accordingly; calculating a matrix Q according to an average amplitude response fluctuation parameter expression of an equilibrium control point in a sound reinforcement target area; solving a vector w according to Rb, Rd and Q to ensure a maximum value of time domain acoustic energy contrast control of single point equilibrium; converting the vector w into a filter form; and acquiring filter parameters of the filter group processing unit (203).

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, the adaptive filter modifying at least one of the adaptive coefficients based on a feedback output. The invention further includes a feedback component that provides the feedback output based, at least in part, upon a non-linear function of the acoustic reverberation reduced output. The invention further provides a noise statistics component that stores noise statistics associated with a noise portion of an input signal and a signal+noise statistics component that stores signal+noise statistics associated with a signal and noise portion of the input signal. The invention further provides a spatial filter that provides an output signal based, at least in part, upon a filtered input signal, the filtering being based, at least in part, upon a weighted error calculation of the noise statistics and the signal+noise statistics.

The invention relates to an earphone which comprises a shell and a loudspeaker, wherein the loudspeaker is arranged in the shell; the shell is made of a magnesium base composite material; the magnesium base composite material comprises magnesium base metal and nano reinforcing phases which are dispersed in the magnesium base metal; and compared with an earphone which has the same shape and adopts a shell made of AZ91D magnesium alloy, the earphone reduces the total harmonic distortion by 10 percent in a frequency range of 20Hz to 50Hz.

The invention provides a loudspeaker array sound reinforcement system generating a uniform sound field, comprising: an input signal processing module (1), a filtering module (2), a multi-channel power amplifier (3) and a loudspeaker array (4); the filtering module (2) comprising: a parameter setting unit (201), a filter bank generating unit (202) and a filter bank processing unit (203); the filter bank generating unit (202) is configured to set The parameter design optimization problem set by unit (201): in the actual sound field energy efficiency is greater than or equal to J _c Under the constraint condition, find a vector solution, make the difference of the actual sound field distribution calculated and target sound field distribution minimum; This vector solution is complex number weight coefficient vector; According to described complex number weight coefficient vector, obtain described filter bank processing unit ( 203) the time-domain impulse responses of the L filters. The sound reinforcement system of the invention can form a uniformly distributed sound field in the target area.

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.

There are provided piezoelectric element, case having conductivity, first acoustic matching layer bonded on case, and second acoustic matching layer stacked on and bonded to first acoustic matching layer. A joining part between first acoustic matching layer and second acoustic matching layer is located inside an outer periphery of a joining surface of first acoustic matching layer that is joined to second acoustic matching layer. This configuration can prevent indirect wave generated in first acoustic matching layer from propagating to second acoustic matching layer, and can therefore reduce reverberation of an ultrasonic wave.

A pain relief device and method or system to aid in the resolution of pain in a body including at least one layer of PVDF film and at least one other layer for directional purposes, as well as a polarizing layer. The device can be packaged in various ways.