Abstract: There is provided a hearing protector that has an earmuff (2) formed by a cup-shaped shell and a cushion. The hearing protector has a sound inlet (5) formed of at least one acoustic membrane that replaces a portion of the shell or by a hole into the cushion. The sound inlet locally reduces the sound barrier of the hearing protector predominantly with respect to sound originating from an anterior direction (11) that is defined in accordance to on the anatomic directions of a wearer when the hearing protector is worn. The present disclosure helps enabling directional hearing with a hearing protector.

Abstract: A host device configured to be wirelessly coupled to an accessory device, the host device comprising noise reduction circuitry, wherein, in use of the host device: a signal generated by a microphone of the accessory device in response to ambient noise is supplied to the noise reduction circuitry; the noise reduction circuitry applies a noise reduction transfer function to the signal supplied thereto to generate a noise cancellation signal; and the noise cancellation signal is supplied to at least one loudspeaker of the accessory device; and wherein the noise reduction transfer function applied by the noise reduction circuitry is user selectable or user adjustable.

Abstract: A method includes detecting, by a speaker system including a microphone, one or more boundaries within a proximity to the speaker system. The speaker system adjusts an output of the speaker system based on the one or more detected boundaries. A sound quality of the speaker system is improved based on adjusting the output.

Abstract: There is described a switchable microphone device which may be switched between a digital output mode and an analog output mode. There is further described a system for use of such a device, which allows for the switching between analog and digital computing modes.

Abstract: This application relates to methods and apparatus for amplification of audio signals with improved audio performance. An audio driving circuit has an amplifier module in a forward signal path between an input for receiving an input audio signal (SIN) and an output for outputting an audio driving signal (VOUT). A pre-distortion module is operable to apply a first transfer function to the signal in the forward signal path upstream of the amplifier module, wherein the first transfer function comprises a non-linear distortion function based on at least one distortion setting. An error block is arranged to receive a first signal (SFF) derived from the input signal and a second signal (SFB) indicative of the voltage of the audio driving signal and determine a first error signal (?1) indicative of a difference between the first and second signals. The pre-distortion module is operable to control the distortion setting(s) based on the first error signal.

Abstract: Implementations disclose filtering wind noises in video content. A method includes receiving video content comprising an audio component and a video component, detecting, by a processing device, occurrence of a wind noise artifact in a segment of the audio component, identifying an intensity of the wind noise artifact, wherein the intensity is based on a signal-to-noise ratio of the wind noise artifact, selecting, by the processing device, a wind noise replacement operation based on the identified intensity of the wind noise artifact, and applying, by the processing device, the selected wind noise replacement operation to the segment of the audio component to remove the wind noise artifact from the segment.

Abstract: A noise cancelling headset includes first and second earpieces, each earpiece including a respective feedback microphone, a respective feed-forward microphone, and a respective output driver. A first feedback filter receives an input from at least the first feedback microphone and produces a first filtered feedback signal. A first feed-forward filter receives an input from at least the first feed-forward microphone and produces a first filtered feed-forward signal. A first summer combines the first filtered feedback signal and the first filtered feed-forward signal and produces a first output signal. An output interface provides the first output signal as an output from the headset.

Abstract: An integrated circuit may include an output for providing a signal to a transducer including both source audio for playback to a listener and an anti-noise signal for countering the effects of ambient audio sounds in an acoustic output of the transducer, a microphone input for receiving a microphone signal indicative of ambient sounds at the transducer, a link control input for receiving link control information of a communications link coupling the integrated circuit to the transducer and/or a microphone for generating the microphone signal, wherein the link control information includes a link quality metric of the communications link, and a processing circuit comprising a filter having a response that generates the anti-noise signal in conformity with the microphone signal to minimize the ambient sounds at the acoustic output of the transducer, wherein the processing circuit modifies generation of the anti-noise signal responsive to the link quality metric.

Abstract: A hearing protection headset that can be worn by a user includes left and right earcups. The headset includes a radio communication system enabling at least one radio signal to be received and played through one or both of the earcups. Noise control circuitry in the headset is configurable by a user between at least three active modes of operation—the circuitry having a first active mode in which the headset provides automatic noise reduction, a second active mode in which the headset provides automatic noise cancellation, and a third active mode in which the headset provides both automatic noise reduction and automatic noise cancellation. A switch is manually operable by the user to configure the circuitry between the first active mode and the second active mode and the third active mode.

Abstract: An electronic circuit for a microphone comprises a first terminal and a second terminal, wherein the electronic circuit is selectively operable in a first mode and a second mode. In the first mode, the first terminal is configured for microphone output and in the second mode, the second terminal is configured for microphone output. Furthermore, a method of operating a microphone is provided.

Abstract: A directivity adjustment device that maintains a constant direct-to-reverberant ratio based on the detected location of a listener in relation to the speaker array is described. The directivity adjustment device may include a distance estimator, a directivity compensator, and an array processor. The distance estimator detects the distance between the speaker array and the listener. Based on this detected distance, the directivity compensator calculates a directivity index form a beam produced by the speaker array that maintains a predefined direct-to-reverberant sound energy ratio. The array processor receives the calculated directivity index and processes each channel of a piece of sound program content to produce a set of audio signals that drive one or more of the transducers in the speaker array to generate a beam pattern with the calculated directivity index.

Abstract: A noise cancelling headset includes first and second earpieces, each earpiece including a respective feedback microphone, a respective feed-forward microphone, and a respective output driver. A first feedback filter receives an input from at least the first feedback microphone and produces a first filtered feedback signal. A first feed-forward filter receives an input from at least the first feed-forward microphone and produces a first filtered feed-forward signal. A first summer combines the first filtered feedback signal and the first filtered feed-forward signal and produces a first output signal. An output interface provides the first output signal as an output from the headset.

Abstract: Described herein are architectures, platforms and methods for implementing an orientation-agnostic mm-wave antenna(s) that includes an integrated second mechanism on a waveguide structure of the mm-wave antenna. The second mechanism, for example, operates on a second signal and is co-running with an operation of the waveguide structure. The second mechanism may include an audio sub-system such as an audio speaker and/or an audio microphone, or other mechanisms such as a sound or a signal detector, signal transmitter/receiver, or the like.

Abstract: A method for noise cancellation. The method includes providing a sound signal output device having a listening device output, a microphone input, and signal processing circuitry. The signal processing circuitry is adapted for causing the sound signal output device to perform in a noise-cancellation mode, including making available to the sound signal output device, at the microphone input, a noise-containing signal which is representative of ambient acoustical noise, deriving a noise-cancelling signal from the noise-containing signal, and making available to the personal listening device, at the listening device output, the noise-cancelling signal.

Abstract: The present application describes bone conduction microphone (BCM) systems and applications thereof. An example apparatus includes: (a) an enclosing structure having a cavity therein, wherein a first portion of the enclosing structure is formed by an elastic material, and wherein the elastic material is moveable to transfer vibration from an exterior source to gas within the cavity; and (b) a microphone coupled to the enclosing structure and located within the gas-filled cavity, wherein gas in the cavity separates the microphone from the first portion of the enclosing structure, such that the vibration transferred from the exterior source to the gas in the cavity is detectable by the microphone.

Abstract: An active-noise-reduction (ANR) headset includes at least one auxiliary connection to an output of at least one device, such as a personal communications, computing, and/or entertainment device. An exemplary headset also includes a primary connection to a two-way radio or public-address system and circuitry for automatically suppressing or muting the volume of an auxiliary input signal relative to that of a primary input signal. Other exemplary features include a headset power supply, a microphone, a microphone preamplifier, and a device-detection circuit. The device-detection circuit selectively couples the power supply to the microphone preamplifier, enabling it to provide audio signals to the microphone input of the auxiliary device.

Abstract: Systems and methods for controlling adaptivity of noise cancellation are presented. One or more audio signals are received by one or more corresponding microphones. The one or more signals may be decomposed into frequency sub-bands. Noise cancellation consistent with identified adaptation constraints is performed on the one or more audio signals. The one or more audio signals may then be reconstructed from the frequency sub-bands and outputted via an output device.

Abstract: A noise canceling system comprises a microphone generating a captured signal and a sound transducer radiating a sound canceling audio signal in the audio environment. A feedback path from the microphone to the sound transducer includes a non-adaptive canceling filter and a variable gain and receives the captured signal and generates a drive signal for the sound transducer. A gain detector determines a secondary path gain for at least part of a secondary path of a feedback loop. The secondary path may include the microphone, the sound transducer, and the acoustic path therebetween but does not include the non-adaptive canceling filter or the variable gain. A gain controller adjusts the in of the variable gain in response to the secondary path gain. The system use simple gain estimation and control to efficiently compensate for variations in the secondary path to provide improved stability and noise canceling performance.

Abstract: The headset comprises two earpieces each having a transducer for playing back the sound of an audio signal and received in an acoustic cavity defined by a shell having an ear-surrounding cushion. The active noise control comprises, in parallel, a feedforward bandpass filter receiving the signal from an external microphone, a feedback bandpass filter receiving as input an error signal delivered by an internal microphone, and a stabilizer bandpass filter locally increasing the phase of the transfer function of the feedback filter in an instability zone, in particular a waterbed effect zone around 1 kHz. A summing circuit delivers a weighting linear combination of the signal delivered by these filters together with the audio signal to be played back. Control is non-adaptive, with the parameters of the filters being static.

Abstract: An active noise control (ANC) system may be implemented to both sides of a fan, such that both directions of the noise emitting are treated to reduce the overall noise. The impact on airflow is minimal, and the technique is very effective in a broad range of low frequencies. Passive sound-absorbing materials may be included for attenuation of high frequencies. The resulting quiet fan produces a low level of noise compared to any other device based on fan, which produces the same capacity of airflow. The quiet fan may be incorporated in any mechanical system which requires airflow induction such as: computers, air conditioners, machines, and more.

Abstract: The invention provides an analog-to-digital converter. In one embodiment, the analog-to-digital converter receives a first audio signal from a microphone, and comprises a coding selection module, a pre-amplifier, a 1-bit ?? modulator, and a signal coding module. The coding selection module receives a mode signal and a channel selection signal, and generates a control signal according to the mode signal and the channel selection signal. The pre-amplifier amplifies the first audio signal to obtain a second audio signal. The 1-bit ?? modulator converts the second audio signal from analog to digital to obtain a third audio signal.

Abstract: Methods and systems for reducing noise relating to an electronic system are disclosed. The methods and systems determine a noise signature, which characterizes a targeted noise of the electronic system. A cancellation signal is then generated based on this noise signature, so that if the cancellation signal is transmitted, the targeted noise is at least partially reduced.

Abstract: A system, method, and program product are provided for filtering sound from a selected application on a computer without interrupting voice communications on the computer. The method comprises: monitoring a selected program for an outgoing digital audio signal from a selected application; detecting said digital audio signal; and filtering an analog microphone input with the digital audio signal.

Abstract: There is provided headphones for connection to an external active noise compensation device. The headphones have at least one earphone, a microphone near the ear, and a passive circuitry network for increasing the amplification of the external noise compensation device. In that way noise compensation in respect of the external noise compensation can be increased by increasing the overall amplification by the passive network.

Abstract: A method, medium, and apparatus for extracting a target sound from a mixed sound. The method includes obtaining the mixed signal from a microphone array, generating a first signal which is emphasized and directed toward a target sound source, and a second signal which is suppressed and directed toward the target sound source, calculating a non-linear filter which is adaptive to at least one of an amplitude ratio of the first signal to the second signal in a time-frequency domain, frequencies of the first and second signals, and a ratio of an interference signal to the mixed signal, and filtering the first signal by the non-linear filter.

Abstract: The present invention relates to a stethoscope auscultation method, adapted for an improved stethoscope so as to be used for assisting a medical diagnosis according to visceral sounds.

Abstract: A stethoscope capable of eliminating unwanted sounds and method thereof, the stethoscope and method thereof mainly use a stethoscope head containing a sensor and a signal processing circuit. By way of detecting and judging whether the stethoscope head arrives on correct stethoscopic position by the sensor, unwanted sounds generating by frictions, translations, or collisions during the stethoscopic process can be effectively eliminated such that the stethoscopic quality can be improved. Thus, a doctor can use less time and spirit to make a correct diagnosis for a patient with least unwanted interference sounds.

Abstract: A dimension measurement system is provided. The dimension measurement system includes a speech I/O device fit in an ear canal of a worker, generating a voice signal from vibration in the air emitted from an eardrum of the worker and propagated inside the ear canal, and outputting the voice signal and an information processing device realizing a speech recognition function recognizing a measurement value of a dimension of an object from the voice signal that the speech I/O device output and a judgment function judging if the measurement value satisfies a reference value of the object.

Abstract: The loudspeaker device according to the present invention comprises a loudspeaker; a feedforward processing section for performing feedforward processing on an electric signal to be inputted to the loudspeaker based on a preset filter coefficient so that non-linear distortion which occurs from the loudspeaker is removed; and a feedback processing section for detecting vibration of the loudspeaker, and performing feedback processing on an electric signal concerning the vibration with respect to the electric signal to be inputted to the loudspeaker. The feedback processing section performs feedback processing on the electric signal concerning the vibration so that the non-linear distortion which occurs from the loudspeaker is removed and so that a frequency characteristic concerning the vibration of the loudspeaker becomes a predetermined frequency characteristic.

Abstract: A noise cancellation system for an audio system such as a mobile phone handset, or a wireless phone headset has a first input for receiving a first audio signal from one or more microphone positioned to receive ambient noise, and a second input for receiving a second audio signal from a microphone positioned to detect the user?s speech, as well as a third input for receiving a third audio signal for example representing the speech of a person to whom the user is talking. A first noise cancellation block receives the first audio signal and generates a first noise cancellation signal, and this is combined with the third audio signal to form a first audio output signal. A second noise cancellation block receives at least a part of the first audio signal and said second audio signal and applying noise cancellation to generate a second audio output signal.

Abstract: The invention is directed to a system and method for noise cancellation for an apparatus such as an electric motors or generator. The system may comprise a plurality of actuators, a plurality of phase controllers, each phase controller receiving an input signal representing a movement of an apparatus and outputting an output signal based on the input signal and at least one predetermined phase shift, and a plurality of amplifiers, each amplifier receiving an output signal from one of the phase controllers and outputting an amplified signal to drive one of the actuators. The method may comprise the steps of generating a first signal representing a movement of the apparatus, generating at least one second signal based on (a) the first signal, (b) at least one predetermined phase shift, and (c) at least one predetermined amplitude, and driving at least one actuator with the at least one second signal.

Abstract: A sound altering apparatus for altering predetermined sound levels of a sound producing device, the sound altering apparatus includes at least one piezoelectric foil sensor disposed relative to the sound producing device with the at least one piezoelectric foil sensor being operable to convert such sound wave energy into an electric sound signal one or more electric circuits in electrical communication with the at least one piezoelectric foil sensor for receiving the electric sound signal and shunting the electric sound signal to a ground connection, or to produce cancelling sound wave energy in the vicinity of the sound producing device, thereby reducing sound heard outside the sound producing device.

Abstract: A passive noise reduction apparatus for altering predetermined sound levels of a sound producing device, the noise reduction apparatus includes at least one piezoelectric foil sensor disposed relative to the sound producing device with the at least one piezoelectric foil sensor being operable to convert such sound wave energy into an electric sound signal and one or more electric circuits in electrical communication with the at least one piezoelectric foil sensor for receiving the electric sound signal and shunting the electric sound signal to a ground connection, thereby reducing sound heard outside the sound producing device.

Abstract: 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.

Abstract: A telephonic handset comprises an active noise reduction (ANR) system. The ANR system comprises a reference microphone and an IIR filter. The IIR filter is receivingly coupled to the reference microphone with respect to noise reference signals, and it is transmittingly coupled to the receiver transducing element of the handset. The ANR system is configured as a fixed feed-forward noise cancellation system. Preferably, the IIR filter has a transfer function derived, in part, from the open-loop gain of a feedback noise cancellation system. In specific embodiments of the invention, the noise reference microphone is situated so as to sample the ambient noise field near the front face of the receiver, but without directly sampling the noise field on the front face.

Abstract: An active noise control system for reducing road noise of low frequency generated inside the cabin of a vehicle is provided. The active noise control system includes a noise detector, a signal generator for processing the input noise signal to generate a signal for producing noise canceling waves, a limiting amplifier having a specified threshold value for variably amplifying the processed signal so that the amplitude of output signal will not exceed the threshold value, and an electrical acoustic converter for producing noise canceling acoustic waves in accordance with the output signal.

Abstract: A phase-locked loop (PLL) circuit generates a sine wave signal synchronized with an input signal. The sine wave signal is directly supplied to a first multiplier. The sine wave signal is also supplied to a second multiplier after shifting the phase by 90 degrees by an all-pass filter (APF). The first and second multipliers multiply the corresponding input signals by corresponding predetermined gains. An adder sums the products. Sound corresponding to the sum is produced from a speaker to a sound field. A filter-controlling unit controls the gains for the first and second multipliers, respectively, to minimize an error signal “e” for the output level of a microphone installed at a listening position.

Abstract: A method and apparatus for actively influencing the intake noise of an internal combustion engine. The apparatus comprises a controller (7) which senses the actual noise (I) via a microphone (16) and compares the actual noise with a reference noise signal which depends on the engine speed D and at least one further engine parameter P, such as, for example, the throttle (12) position. A comparison signal V generated by comparing the actual noise to the reference noise value is used to adjust a control signal Asum, which also depends on the engine speed D. The control signal is fed to an electromechanical transducer (14) which generates a correcting noise (20) which is superimposed on the intake noise (21) to produce the resultant actual noise (22), which should correspond as closely as possible to the reference noise value.

Abstract: An Automatic Noise Reduction system wherein the Q of the frequency response is reduced using a negative output resistance to substantially eliminate the coil resistance of a speaker in a headset. The resulting system is less sensitive to variations in operating parameters, such as headset fit on a user and component variations. Temperature compensation of a negative output resistance amplifier is introduced to maintain stability over a wide range of operating temperatures. Temperature compensation includes substantially matching the temperature coefficient of the negative output resistance amplifier to the temperature coefficient of the speaker coil.

Abstract: A method for processing a sound signal is proposed, which is applied to a signal processing system including a signal receiving device, a signal recognizing device and a signal processing device. The signal recognizing device is used to distinguish the sound signal received from the signal receiving device into a sound source signal and background interference, so as to eliminate the background interference and transfer the sound source signal to the signal processing device. In this case, the signal processing device merely processes and amplifies the sound source signal, and thus no filtering circuit is required for the elimination of the background interference.

Abstract: A broadcast receiving system incorporating an echo canceling means automatically initiates recording of the broadcast and also controls the sound volume by taking into account the viewer's movements and ambient conditions, by using echo canceling means of the type used in hand-free telephones. The broadcast receiving system includes a broadcast receiving unit for receiving a broadcast in the form of either digital or analog signals; an echo canceling unit; and a determining unit for monitoring the amount of residual echoes in the echo canceling unit, determining whether the amount of residual echoes has exceeded a predetermined value, and instructing a storage unit to store the broadcast if the amount of residual echoes is found to have exceeded the predetermined value.

Abstract: noise extraction method in which an environmental input which includes a noise indicia is selectively modified in accordance with an algorithm that includes one or more factors representing time response, amplitude of response, and error correction. The algorithm may also include thresholding delay or convergence, among other techniques.

Abstract: A system and method for actively damping boom noise within an enclosure such as an automobile cabin. The system comprises an acoustic wave sensor, a motion sensor, an acoustic wave actuator, a first electronic feedback loop, and a second electronic feedback loop. The enclosure defines a plurality of low-frequency acoustic modes that can be induced/excited by the enclosure cavity, by the structural vibration of a panel of the enclosure, by idle engine firings, and a combination thereof. The acoustic wave actuator is substantially collocated with the acoustic wave sensor within the enclosure. The motion sensor can be secured to a panel of the enclosure.

Abstract: A filtering device consisting of a nonadaptive feedback filter that generates active attenuation of the vibration on the framework, without generating instability in a first frequency band, and an adaptive feedforward filter is disclosed. Feedforward filtering coefficients are adapted in real time according to an algorithm chosen to minimize the energy of the types of vibration which are picked up by a sensing device as a function of the energy of the types of vibration which are picked up by the sensing device, and of the previously measured transfer function, in the presence of a feedback filtering device and in the absence of a feedforward filtering device, between an actuator device and a first sensing device. The device makes it possible to linearize the feedback attenuation throughout a second frequency band which is wider than the first frequency band, to accelerate the convergence of the minimization algorithm and to enhance the robustness of the feedforward filter.

Abstract: A process for determining an estimated value for the noise level n of a background noise superimposed on an acoustic useful signal is characterised in that the estimated value n(x) for a sampled input signal x(k) is defined as a value n1(x) which is determined by means of the minimum value of the quantity of all the successive maximum values of the input signal x(k) in each case found within a short time interval ts≧1 ms; that the value n1(x) is adopted as estimated value n(x) for the current noise level n when the dynamic variations of the input signal x(k) undershoot a threshold value &egr;; and that otherwise the estimated value determined in the preceding step is adopted unchanged as new estimated value n(x). In this way it is possible to achieve an extremely exact determination of the current noise level with very fast adaptation times which are considerably shorter than in known processes, with the need for only a relatively small computation outlay.

Abstract: An adaptive noise rejection method and apparatus. An information signal having an information component and a repetitive noise component having a varying characteristic frequency is delayed the information signal by a reference delay time that is equal that is equal to a predetermined number of periods of the characteristic frequency to form a delayed information signal. The delayed information signal is subtracted from the information signal to form a processed information signal in which the information component is substantial and the noise component is negligible. The amplitude of the noise component of the processed information signal is constantly monitored. The delay of the information signal is varied as the characteristic frequency of the noise component changes so as to maintain the amplitude of the noise component of the processed information signal at a predetermined level.

Abstract: An adaptive noise rejection method and apparatus. An information signal having an information component and a repetitive noise component having a varying characteristic frequency is delayed the information signal by a reference delay time that is equal that is equal to a predetermined number of periods of the characteristic frequency to form a delayed information signal. The delayed information signal is subtracted from the information signal to form a processed information signal in which the information component is substantial and the noise component is negligible. The amplitude of the noise component of the processed information signal is constantly monitored. The delay of the information signal is varied as the characteristic frequency of the noise component changes so as to maintain the amplitude of the noise component of the processed information signal at a predetermined level.

Abstract: The method of noise attenuation comprises the steps of generating a noise canceling signal, sensing for an system condition, and ceasing the generation of the noise canceling based upon the system condition. This method is embodied in a system that includes an air induction body, a speaker in proximity to the air induction body, a sensor for sensing a system condition, and a control unit with a noise cancellation feature. The control unit is in communication with both the speaker and the sensor. Based upon the sensed system condition, the control unit may disable the noise cancellation feature.

Abstract: An active noise cancellation aircraft headset system. A speaker is mounted within each earcup of a headset for receiving and acoustically transducing a composite noise cancellation signal. A microphone is also mounted within each earcup for transducing acoustic pressure within the earcup to a corresponding analog error signal. An analog filter receives the analog error signal and inverts it to generate an analog broadband noise cancellation signal. The analog error signal is also provided to an analog to digital converter, which receives the analog microphone error signal and converts it to a digital error signal. A DSP takes the digital error signal and, using an adaptive digital feedback filter, generates a digital tonal noise cancellation signal. A digital to analog converter then converts the digital tonal noise cancellation signal to an analog tonal noise cancellation signal so that it can be combined with the analog broadband noise cancellation signal.

Abstract: A noise environment is sampled via microphone. A processor generates a cancellation signal to offset the effects of the noise to a listener. The cancellation signal is converted into a sample signal compatible with a synthesizer. The synthesizer adjusts the pitch, amplitude and timing of a sample of a patch set to create a substantially continuous output cancellation signal. The continuous output cancellation signal is output via a speaker. The output cancellation signal combines with the noise environment to reduce the effects of the noise environment on the listener. Alternatively, in previously characterized noise environments, one or more cancellation signals may be stored in processor. The processor receives a user input selecting the appropriate cancellation signal and adjusting the parameters of the cancellation signal.