207results about How to "Reduce environmental noise" patented technology

Techniques for canceling echo and suppressing noise using an array microphone and signal processing. In one system, at least two microphones form an array microphone and provide at least two microphone input signals. Each input signal may be processed by an echo canceller unit to provide a corresponding intermediate signal having some echo removed. An echo cancellation control unit receives the intermediate signals and derives a first gain used for echo cancellation. A noise suppression control unit provides at least one control signal used for noise suppression based on background noise detected in the intermediate signals. An echo cancellation and noise suppression unit derives a second gain based on the control signal(s), cancels echo in a designated intermediate signal based on the first gain, and suppresses noise in this intermediate signal based on the second gain. The signal processing may be performed in the frequency domain.

A handheld diagnostic ultrasound device is disclosed which is pocket sized, lightweight and is designed for clear imaging under adverse lighting conditions by utilizing a custom Head Mounted Display (HMD). The handheld diagnostic ultrasound device comprises a removable probe and a removable HMD that connects to the personal digital assistant (PDA) style control unit. The handheld diagnostic ultrasound device may be viewed on the VGA LCD Display on the diagnostic ultrasound device or on the HMD. Images obtained may be stored to a secure digital flash or transferred via USB (Universal Serial Bus) or wireless link to a remote computer system for further processing or archiving. The handheld diagnostic ultrasound device is based on a dual-core processor that achieves a level of integration not previously attainable in a handheld diagnostic ultrasound device.

Improved vocal signals are obtained in headsets and similar devices by including a microphone inside a chamber formed at least in part by the wearer's ear. This second microphone provides a reduced noise input signal. The reduced noise signal is corrected by input from another microphone, located outside the chamber. This correction can include echo cancellation, spectral shaping, frequency extension, and the like.

The technology of active noise reduction (ANR) is incorporated into audiometry testing in a variety of formats. Analog feedback, digital feedback, adaptive feedforward, and adaptive feedback noise control schemes are presented for use in audiometry to reduce the ambient noise heard by the test subject, allowing subject testing in higher ambient noise fields. Audiometer test signals are appropriately compensated so the test results are accurate and comply with existing calibration standards for audiometers. Existing audiometry headphone technologies are modified so that ANR can be accomplished while satisfying existing standards for audiometric testing. Embodiments are also defined for alternate headphone arrangements that may not conform to current (1997) audiometric testing standards but provide sufficient performance advantages to warrant new standards for audiometry testing in the future.

A chest piece for a stethoscope has a housing with a cavity. The cavity has a cavity surface which is paraboloid in shape, having an apex, an axis, and a focal point. The cavity terminates at the apex and an opening, and the focal point resides in the cavity. A transducer is positioned at the focal point. The parabolic shape of the cavity surface acts to reflect sound waves transmitted normal to the opening to the transducer, while reflecting other sound waves. A mechanical wave guide with a series of parallel passages preferably extends across the opening. Preferably, a membrane with a convex surface covers the opening. The cavity is preferably filled with a liquid or gel having physical characteristics similar to human flesh. To reduce noise from motion of the chest piece across the skin, the stethoscope can be activated by a pressure switch responsive to fluid pressure inside the cavity.

An active noise control system for use in testing hearing using a pure tone audiometry testing procedure and employing multiple switching controllers with pre-filtering means and a switch to select any one controller to provide a predetermined one and having the ability to configure each switching controller so that the maximum threshold shift occurs for the frequency of the test tone and for modifying each test tone in accordance with a standard calibration frequency.

A differential non-contact sensor system for measuring biopotential signals is described. The sensor is a low-noise, non-contact capacitive sensor system to measure electrical voltage signals generated by the body comprising two capacitive electrodes and outputting a differential signal.

A Personal Noise Reduction for enclosed cabins is disclosed. According to one embodiment, an input audio source corresponding to sound received from multiple microphones situated equidistantly in both directions in a two dimensional plane, is converted to a digital signal via an analog to digital (A/D) convertor. The AID converted audio is analyzed for content to identify ambient noise. The frequency, amplitude and phase of the identified ambient noise is subsequently determined. A Noise correction sound wave is generated with negative phase of that corresponding to the identified ambient noise. The noise correction sound wave is added to the identified noise to create a noise corrected sound.

A method and system for blind channel estimation comprises acquiring two mixtures of at least one at least weakly W-disjoint orthogonal source signal, calculating point-by-point ratios of a transform of a time-window of each of said mixture signals, determining channel parameter estimates from said ratios, constructing a histogram of said channel parameter estimates, repeating the calculating, determining and constructing steps for successive time windows of the mixture signals, and selecting as estimates of said channel parameters those estimates associated with identified peaks on said histogram.

An audio headphone apparatus having ambient noise isolation properties for musicians and sound engineers which allows a user to substantially attenuate ambient noise levels and focus on the electronic audio presented to the headphones. The apparatus utilizes a unique layering of absorber materials with unique geometric shapes which in combination highly attenuate external ambient acoustic energy and control undesirable “boomy” bass response. The apparatus further utilizes a desiccant material within the ear cuff cover which helps to absorb perspiration or other moisture.

A kit for preparing a custom-fit ear protection molding is provided having a first container containing a compliant material and a second container containing a hardening agent such that when the compliant material and the hardening agent are combined and kneaded, a resulting compound is formed which may be inserted into the ear of a user and allowed to cure. A method of affecting the hearing of a user is provided. A method of selling a hearing-protection kit is also provided along with a method of manufacturing the disclosed kit.

Active noise reduction headphones for audiometry where the earphone portion of said headphones has a cavity volume greater than 6 cc and including an acoustic-electric sensing means and an electro-acoustic transducing means which are used cooperatively and which has additional passive noise control means in the form of a circumaural seal around the ear for improving high frequency noise control performance, the headphone having a summing junction for combining the active noise reduction signal and an audiometry test signal.

A gaming machine in a gaming establishment enhances its game sounds by attenuating ambient noise in the establishment. The gaming machine includes a microphone, processing circuitry, and an audio speaker. The microphone detects ambient noise and generates a noise signal from the sensed ambient noise. The processing circuitry generates an anti-noise signal from the noise signal and adds the anti-noise signal to a game sound signal generated by the gaming machine to produce an output signal. The audio speaker is driven with the output signal.

An audio system comprises, according to one aspect of the invention, an audio frequency actuator coupled to a body so as to cause the body to radiate sound when an audio signal is supplied to the actuator by a controller, and an acoustic sensor coupled to said body or to an adjacent body so as to sense acoustic vibrations in said body, the sensor being connected to the controller, whereby the controller is arranged to change the audio signal supplied to the actuator according to the vibrations sensed by the sensor. Another aspect provides an audio system comprising an audio frequency actuator coupled to a body so as to cause the body to radiate sound when an audio signal is supplied to the actuator by a controller, and an acoustic sensor coupled to said body or to an adjacent body so as to sense acoustic vibrations in said body, the sensor being connected to the controller, whereby the controller is arranged to detect predetermined characteristics of the sensed acoustic vibrations and to output an alerting signal in response thereto.

Active noise cancellation may be provided by a variety of systems, methods and techniques. General aspects, for example, include an active noise cancellation system, a controller for an active noise cancellation system, and/or a method of generating an anti-noise signal. In one example aspect, an active noise cancellation system for an aircraft In-flight entertainment system may include at least one input device, a processing means, and an output. The input device may be associated with a seat on the aircraft and adapted to receive an input representative of an ambient noise in the vicinity of the seat. The processing means may be adapted to process the input to produce an output signal adapted to reduce the ambient noise in volume associated with the seat. The output may be adapted to transmit an output signal to at least one driver, which is adapted to transmit the output signal to a user.

The present invention provides a wireless electronic device for audio signal procession and transmission. In one embodiment, the wireless electronic device comprises a primary unit being worn on one ear of a user, wherein the primary unit comprises a main electrical circuitry for receiving, processing, and transmitting audio signals, wherein the audio signals may be received from different sources; a speaker being electronically coupled to the main electrical circuitry for outputting the processed audio signals to a user; a microphone being electronically coupled to the main electrical circuitry for audio signal inputting to the main electrical circuitry; an interface being electronically coupled to the main electrical circuitry for allowing connection with a secondary attachment; and a power source for powering the wireless electronic device; whereby when the interface is not connected with the secondary attachment, the wireless electronic device functions as a mono headset.

A microphone assembly generally for hearing aid and communications applications is disclosed. The microphone assembly operates in both directional and non-directional or omni-directional modes. The microphone assembly has front and rear sound inlet tubes, and an actuator switch that may be moved between a first position in which the rear tube is plugged, defining the omni-directional mode, and a second position in which the rear tube is unplugged, defining the directional mode. Circuitry senses the position of the actuator switch and selects a microphone output based on the position sensed.

The invention discloses an Ausferrite ductile cast iron grinding ball, and relates to a spherulitic graphite-contained cast iron alloy. The Ausferrite ductile cast iron grinding ball comprises the following chemical elements in percentage by mass: 3.3-3.7% of C, 2.0-3.0% of Si, 1.0-2.5% of Mn, 0.7-3.0% of Cr, 0.1-1.0% of Mo, 0.1-1.0% of Cu, 0.04-0.08% of P, 0.01-0.020% of S, 0.03-0.05% of Mg, 0.02-0.04% of Ce, 0.03-0.07% of B, 0.06-0.12% of Ti, 0.03-0.2% of V, and the balance of Fe. The Ausferrite ductile cast iron grinding ball is prepared by the steps of preparation and smelting of raw materials, spheroidizing treatment, inoculation treatment and microalloying treatment, and isothermal quenching heat treatment. The Ausferrite ductile cast iron grinding ball overcomes the defects of low production efficiency and high consumption of electric energy of a ball mill due to easy surface stripping and crushing and shorter fatigue life of an existing grinding ball product in the service process.

A volume adjusting apparatus includes a sound collecting unit configured to collect noise data of a surrounding environment, an analyzing unit configured to extract a feature value indicating a feature of the noise data collected by the sound collecting unit and a feature value indicating a feature of supplied musical tune data, and a control unit configured to generate volume adjustment information for adjusting playback volume of the musical tune data based on the feature value of the noise data and the feature value of the musical tune data and adjusts the playback volume of the musical tune data based on the volume adjustment information.

The invention relates to a multi-mode pedestrian safety sound warning system for an electric vehicle and belongs to the technical field of automobile safety. The system comprises a pedestrian detection module, a vehicle condition detection module, an environmental noise detection module, a waveform storage module, a central processor and a sound output module, wherein the pedestrian detection module is used for detecting whether pedestrians appear right ahead the vehicle; the vehicle condition detection module is used for acquiring the operating working condition of the electric vehicle; the environmental noise detection module is used for acquiring an environmental noise signal; the waveform storage module is used for storing waveforms corresponding to each module; the central processor is used for selecting corresponding sound waveform signals after judging the acquired signals; and the sound output module is used for selecting sound to play. The sound warning system disclosed by the invention is used for automatically controlling the output warning sound according to the environmental noise so as to reduce unnecessary environmental noise; and the used sound waveforms are subjected to filtering processing, so that the interference of the sound signals on the surrounding environment is furthest weakened and the driving cheerfulness is also ensured.

A Noise Cancellation Process for enclosed cabins is disclosed. According to one embodiment, an input audio source corresponding to sound received from multiple microphones situated equidistantly in both directions in a two dimensional plane, is converted to a digital signal via an analog to digital (A/D) convertor. The A/D converted audio is analyzed for content to identify ambient noise. The frequency, amplitude and phase of the identified ambient noise is subsequently determined. A Noise correction sound wave is generated with negative phase of that corresponding to the identified ambient noise. The noise correction sound wave is added to the identified noise to create a noise corrected sound.

A noise reduction scheme is incorporated into a computer system for reducing environmental background noise when a user is listening to audio output through a standard set of headphones. The noise reduction scheme utilizes the processing power of the computer system as well as built-in components of the computer for enhancing the audio quality heard by the user. Environmental background noise is received by a built-in microphone, wherein a reciprocal noise canceling signal is generated by the computer's microprocessor. The reciprocal noise canceling signal is then mixed with audio from the computer system for reducing the environmental background noise heard by a user.

Methods of measuring flow properties and flowmeters having an upstream transceiver and a downstream wave transceiver, each positioned with a wave emitting surface exposed to a fluid flowing in a conduit are described, the transceiver being separated by a length L along the conduit and adapted to receive wave signals traveling in flow direction and opposite to the flow direction, respectively, and an electronic processor for extracting from travel time measurements of the wave signals flow characterizing parameters, the transceivers being adapted to generate tube waves, particularly in the audible frequency range, in the conduit and used to determine the travel time of the tube waves between the upstream transceiver and the downstream wave transceiver.