6321 results about "Frequency response" patented technology

An active noise cancellation system includes a series of features for more effective cancellation, greater reliability, and improved stability. A particular feature adapted for headset systems includes locating a residual microphone radially offset from the center of a sound generator to detect a signal more similar to that incident upon the eardrum of the user. In addition, an open back headset design includes perforations on the side of the headset instead of the back, so that the perforations are less susceptible to inadvertent blockage. The system also includes a mechanism for detecting changes in the acoustic characteristics of the environment that may be caused, for example, by pressure exerted upon the earpieces, and that may destabilize the cancellation system. The system automatically responds to such changes, for example, by reducing the gain or the frequency response of the system to preserve stability. The system further includes other methods for detecting imminent instability and compensating, such as detecting the onset of signals within enhancement frequencies characteristic of the onset of instability, and adjusting the gain or frequency response of the system or suppressing the enhanced signals. The system further includes a mechanism for conserving battery life by turning the system off when sound levels are low, or adjusting the power supply to the system to correspond to the current power requirements of the system.

The invention relates to a listening assistance device (1) comprising hearing modules (3) mounted on the ends of the arms of an eyeglass frame (2), said modules being designed to support the eyeglass frame on the ear of the user. The hearing modules also have a formed part (5) which extends into the auditive canal without closing the latter and which includes the sound outlet hole (6) of the module. The modules comprise a speech spectrum frequency response and linear dynamics in order to improve speech intelligibility. This makes it possible to provide a listening assistance device compensating for mild hearing loss that can be produced easily and economically, is more comfortable to use and is not regarded at first sight as a hearing aid by an observer.

A micro-actuator is comprised of a piezoelectric motor mounted on a flexure tongue with offsetting hinges, to perform a fine positioning of the magnetic read/write head. The substantial gain in the frequency response greatly improves the performance and accuracy of the track-follow control for fine positioning. The simplicity of the enhanced micro-actuator design results in a manufacturing efficiency that enables a high-volume, low-cost production. The micro-actuator is interposed between a flexure tongue and a slider to perform an active control of the fly height of the magnetic read/write head. The induced slider crown and camber are used to compensate for thermal expansion of the magnetic read/write head, which causes the slider to be displaced at an unintended fly height position relative to the surface of the magnetic recording disk. The enhanced micro-actuator design results in reduced altitude sensitivity, ABS tolerances, and reduced stiction. The controlled fly height of the magnetic read/write head prevents a possibility of a head crash, while improving the performance and data integrity.

Described herein is a probe card assembly providing signal paths for conveying high frequency signals between bond pads of an integrated circuit (IC) and an IC tester. The frequency response of the probe card assembly is optimized by appropriately distributing, adjusting and impedance matching resistive, capacitive and inductive impedance values along the signal paths so that the interconnect system behaves as an appropriately tuned Butterworth or Chebyshev filter.

A method and an apparatus for reproducing a sound signal are provided. The method includes generating an output sound signal to be transmitted to speakers by transmitting a first input sound signal through a filter; acquiring magnitude information of the output sound signal; determining frequency response parameters related to frequency responses of the filter based on the magnitude information; and adaptively adjusting coefficients of the filter based on the determined frequency response parameters.

Methods and apparatus for screening diverse arrays of materials are provided. In one aspect, systems and methods are provided for imaging a library of materials using ultrasonic imaging techniques. The system includes one or more devices for exciting an element of the library such that acoustic waves are propagated through, and from, the element. The acoustic waves propagated from the element are detected and processed to yield a visual image of the library element. The acoustic wave data can also be processed to obtain information about the elastic properties of the library element. In another aspect, systems and methods are provided for generating acoustic waves in a tank filled with a coupling liquid. The library of materials is then placed in the tank and the surface of the coupling liquid is scanned with a laser beam. The structure of the liquid surface disturbed by the acoustic wave is recorded, the recorded disturbance being representative of the physical structure of the library. In another aspect of the invention, a mechanical resonator is used to evaluate various properties (e.g., molecular weight, viscosity, specific weight, elasticity, dielectric constant, conductivity, etc.) of the individual liquid elements of a library of materials. The resonator is designed to ineffectively excite acoustic waves. The frequency response of the resonator is measured for the liquid element under test, preferably as a function of time. By calibrating the resonator to a set of standard liquids with known properties, the properties of the unknown liquid can be determined. An array of library elements can be characterized by a single scanning transducer or by using an array of transducers corresponding to the array of library elements. Alternatively, multiple resonators of differing design may be used to evaluate each element of a library of elements, thus providing improved dynamic range and sensitivity.

A hearing-aid device and a method for transmitting sound through bone conduction are disclosed. The hearing-aid device comprises a piezoelectric-type actuator, housing and connector. The piezoelectric actuator is preferably a circular flextensional-type actuator mounted along its peripheral edge in a specifically designed circular structure of the housing. During operation, the bone-conduction transducer is placed against the mastoid area behind the ear of the patient. When the device is energized with an alternating electrical voltage, it flexes back and forth like a circular membrane sustained along its periphery and thus, vibrates as a consequence of the inverse piezoelectric effect. Due to the specific and unique designs proposed, these vibrations are directly transferred trough the human skin to the bone structure (the skull) and provide a means for the sound to be transmitted for patients with hearing malfunctions. The housing acts as a holder for the actuators, as a pre-stress application platform, and as a mass which tailors the frequency spectrum of the device. The apparatus exhibits a performance with a very flat response in the frequency spectrum 200 Hz to 10 kHz, which is a greater spectrum range than any other prior art devices disclosed for bone-conduction transduction which are typically limited to less than 4 kHz.

The subject matter of the present invention is a method for monitoring a photovoltaic generator (1) for generating current with a number of solar cells connected between two external connections by repeated feeding of a current with a frequency spectrum into the generator current circuit, detecting thereby a respective frequency response in the frequency spectrum with the supplied current as the input variable and an electric variable of the generator as the output variable, and detecting a change in the frequency response for monitoring the photovoltaic generator (1) in the event of a change during repeated feeding.

A wireless communication device includes, in part, an analog interference cancellation circuit and a controller. The analog cancellation circuit includes a multitude of delay paths each including a delay element and a variable attenuator. The controller dynamically varies the attenuation level of each of the variable attenuators in accordance with the frequency response characteristic of that attenuator to remove a portion of a self-interference signal present in a signal received by the device. The device measures the frequency response characteristic of the communication channel, used in determining the attenuation levels, via one or more preamble symbols. A second portion of the self-interference signal is removed by the device using a multitude of samples of a transmitted signal and a multitude of samples of a signal to be transmitted.

An OLED display device for displaying a color image includes an array of different colored independently controllable light emitting elements arranged in repeated patterns, a number of light emitting elements of at least one color in each pattern being different than a number of light emitting elements of a different color and the different number of light emitting elements of the different colors being a function of a relative human visual frequency response to the colors, and a relative size of light emitting elements of different colors being a function of a lifetime of the light emitting elements, an efficiency of the light emitting elements, and the number of light emitting elements of the different colors in the pattern, wherein at least one of the lifetime, and the efficiency is different for different colors.

The film bulk acoustic resonator (FBAR) device comprises a substrate, an acoustic Bragg reflector over the substrate, a piezoelectric element over the acoustic Bragg reflector, and a remote-side electrode over the piezoelectric element. The acoustic Bragg reflector comprises a metal Bragg layer juxtaposed with a plastic Bragg layer. The large ratio between the acoustic impedances of the plastic material of the plastic Bragg layer and the metal of the metal Bragg layer provides sufficient acoustic isolation between the FBAR and the substrate for the frequency response of the FBAR device to exhibit minor, if any, spurious artifacts arising from undesirable acoustic coupling between the FBAR and the substrate.

A method of characterizing a tissue present in a predetermined location of a body of a subject, the method comprising: generating mechanical vibrations at a position adjacent to the predetermined location, the mechanical vibrations are at a frequency ranging from 10 Hz to 10 kHz; scanning the frequency of the mechanical vibrations; and measuring a frequency response spectrum from the predetermined location, thereby characterizing the tissue.

Intelligibility of a human voice projected by a loudspeaker in an environment of high ambient noise is enhanced by processing a voice signal in accordance with the frequency response characteristics of the human hearing system. Intelligibility of the human voice is derived largely from the pattern of frequency distribution of voice sounds, such as formants, as perceived by the human hearing system. Intelligibility of speech in a voice signal is enhanced by filtering and expanding the voice signal with a transfer function that approximates an inverse of equal loudness contours for tones in a frontal sound field for humans of average hearing acuity.

A device comprising a voice activity detector for detecting voice activity in a speech signal using digital data formed on the basis of samples of an audio signal. The voice activity detector comprises a first element adapted to examine whether the signal has a highpass nature. The voice activity detector also comprises a second element adapted to examine the frequency spectrum of the signal. The voice activity detector is adapted to provide an indication of speech when the first element has determined that the signal has a highpass nature or the second element has determined that the signal does not have a flat frequency response.

Systems and methods for optimizing speaker performance. The system includes a self-contained speaker unit that includes a speaker, an amplifier coupled to the speaker, and a processor coupled to the amplifier. The processor receives a first sound signal from a receiver and a second sound signal from a microphone, processes the first sound signal based on a plurality of parameters, outputs the processed sound signal to the speaker, and generates a video signal based on the second sound signal. A wireless remote control allows a user to manipulate the parameters. The processor generates a test sound signal and outputs it to the receiver. The receiver processes the test sound signal and returns it to the processor for output through the speaker. The video signal includes a graphical user interface having a frequency response graph of the second sound signal and an eight band equalizer.

An ultrasonic surgical apparatus including a first signal generator outputting a drive signal at a predetermined voltage and frequency, a first oscillating structure receiving the drive signal and oscillating at the frequency of the drive signal, and a bridge circuit, detecting the mechanical motion of the first oscillating structure and outputting a signal representative of the mechanical motion. The apparatus also includes a second oscillating structure integrally formed within a portion of the first oscillating structure, the second oscillating structure outputting an electrical signal, and a microcontroller receiving the signal output by the bridge circuit and output by the second oscillating structure, the microcontroller determining an instantaneous frequency at which the first oscillating structure is oscillating based on the received signal, comparing the electrical signal from the second oscillating structure with a known signal value and determining the temperature of the second oscillating structure based on a the comparison.

A piezoelectric resonator of the present invention is structured such that on a substrate 5 having a cavity 4 formed therein, a lower electrode 3, a piezoelectric body 1, a spurious component control layer 16, and an upper electrode 2 are formed in this order from bottom up. The spurious component control layer 16 is a layer for controlling a spurious frequency, and composed of, for example, a metallic material, a dielectric material, or a piezo electric material. By additionally providing the spurious component control layer 16, it is made possible to cause variation of the spurious frequency due to unwanted variation to become greater than variation in resonance frequency of the main resonance of the piezoelectric resonator. Thus, it is possible to realize a piezoelectric resonator having an admittance frequency response where no spurious component occurs between resonance frequency fr and antiresonance frequency fa.