Abstract: A method for influencing noise in a space, such as an open-space office, whereby active sound suppression and/or sound masking is/are undertaken. In order to advantageously undertake active sound suppression or sound masking in a larger space, for example an open-space office, a plurality of sound actuators are provided distributed over the surface area of the space, and at least one sound sensor is disposed in the space, and two or more of the sound actuators are acted on differently, with regard to sound values detected by the sound sensor and/or with regard to a desired sound-related space division and/or as the result of person signals or object signals that are detected.

Abstract: Methods of processing audio to convey auxiliary information hidden therein are provided. Various arrangements are disclosed. One alters data representing audio to include a sequence of bits of auxiliary information. The altering is based on a carrier signal and corresponding to the sequence of bits, and is based on a perceptibility threshold that varies within the data representing audio. Other arrangements are provided as well.

Abstract: A method for measuring performance of a noise cancellation system that is operable to cancel noise is provided. The method includes generating a first model of a target noise. The first model represents the target noise in a form that is received at a location remote from a noise source of the target noise and within a defined environment. The method also includes generating a second model of a cancellation noise. The cancellation noise is configured to at least partially cancel the target noise when combined with the target noise. The second model represents the cancellation noise in a form that is received at the location. The method also includes determining, using the first model and the second model, a cancellation error value indicative of only a portion of the target noise that remains when the target noise and the cancellation noise are combined.

Abstract: Mute circuits capable of eliminating audible noise when the audio system is powered up and powered down are disclosed. A discharge element is coupled between an audio processing unit and an audio output unit in an audio system and a mute control unit is coupled to the discharge element. The mute circuit comprises an active element comprising a control terminal coupled to at least one power voltage at a power terminal of a functional element in the audio processing unit through a capacitor and turning on, by AC capacitor coupling, to drive the discharge element when the audio system is powered up, such that the discharge element is turned on to discharge an output current of the audio processing unit to a ground terminal, thereby muting the audio output unit to eliminate audible noise.

Abstract: A method for determining leakage factors or adaptation rates, or both, for adaptive filters in an active noise reduction system. The leakage factor or adaptation rate, or both, may vary depending on a parameter of an input reference signal. The parameter may include one or more of reference signal input frequency, rate of change of reference input signal frequency, if a predetermined triggering condition exits, or if a predetermined event has occurred.

Abstract: This invention is a wearable device that masks and/or cancels annoying ambient sounds to help a person sleep. It includes a soft and stretchable member, such as a headband or hat, that contains one or more sound-conducting tubes. Sound that is emitted from the one or more tubes helps to mask and/or cancel annoying ambient sounds. Advantages of this device over prior art include: no speakers or other rigid components over a person's ears that can be uncomfortable or unsafe when the person sleeps on their side; a relatively wide sound-emitting area to accommodate different size and shape heads; and a stretchable wearable member that gently clings to the person's head to avoid having sound-emitting areas shift away from the person's ears as they toss and turn in their sleep.

Abstract: Disclosed are methods and devices for controlling the state of a fan of an electronic device during audio output based in whole or in part on loudness data of a digital audio file. An audio data file is sampled so that loudness data is determined from the sample audio data. The loudness data may indicate at least one portion of the audio data file that has a predetermined loudness level. For example, when the loudness data indicates that the audio output is low, the fan can be deactivated or slowed. In this way the noise of the fan does not impair the user's audio experience. Alternatively, when the loudness data indicates that the audio output is high, the fan can be activated or its speed may be increased. The predetermined loudness level of the audio output may have a value that is sufficiently high to mask fan noise.

Abstract: The invention relates to an earphone (1) with leakage control, which can be switched between states with and without leakage to adapt the earphone to different listening situations. The leakage of the earphone may be enabled and disabled automatically in dependence of the sound source and/or may be controlled manually by the user. The earphone is connectable to a device and comprises: a housing (2) substantially covering the external auditory meatus, and accommodating a loudspeaker element (3); the housing further comprising a channel (4) extending between an inner end (5) facing the external auditory meatus, and an outer end (6) facing the environment; and closure means (7) being switchable between a closed state in which said channel is substantially closed, and an open state in which said channel is admitting sound from the environment. The invention also relates to a device co-operating therewith, such as a mobile telephone.

Abstract: In an audio encoding system that divides frames generated from input signals into multiple scale factor bands and that encodes each of the scale factor bands by using a scale factor, the invention provides a rate control apparatus that performs rate control based on an NMR, the rate control apparatus comprising an NMR determination unit that determines an NMR that does not exceed a target rate by a binary search; and a scale factor determination unit that determines, by a binary search, the largest scale factor corresponding to the NMR determined by the NMR determination unit and a rate. Each time the NMR determination unit selects an NMR candidate value that acts as a candidate when the NMR determination unit searches for an NMR by a binary search, the scale factor determination unit determines the scale factor corresponding to the NMR candidate value.

Abstract: A method and device for transforming ambient audio are provided. Example embodiments may include monitoring ambient audio proximate to a sound processing device located in an environment. The device may analyze the ambient audio to derive one or more first characteristics. Memory may be accessed to obtain at least one transformation audio from a number of stored transformation audio. Each stored transformation audio may have one or more associated characteristics. A characteristic associated with the transformation audio may match one or more of the first characteristics. The device may generate output transformation audio based on the one or more transformation audio to provide modified output audio for propagation into the environment.

Abstract: A method and device for transforming ambient audio are provided. Example embodiments may include monitoring ambient audio proximate to a sound processing device located in an environment. The device may access memory to obtain transformation audio and generate output transformation audio based on the transformation audio and the ambient audio to provide modified output audio for propagation into the environment. The device may at least reduce feedback of the modified output audio received by the sound processing device from the environment.

Abstract: In a noise reduction apparatus for controlling noise up to a predetermined upper limited frequency, a distance from a noise source to control point X is made larger than a distance obtained by subtracting a one-half wavelength from a distance, obtained by adding up a distance from the noise source to a noise detecting microphone, a distance corresponding to time as a sum of respective delay time of the noise detecting microphone, a noise controller, and a control speaker, and a distance from the control speaker to control point X, where one wavelength is a period corresponding to the upper limited frequency.

Abstract: Method and arrangement in an audio handling entity, for damping of dominant frequencies in a time segment of an audio signal. A time segment of an audio signal is obtained, and an estimate of the spectral density or “spectrum” of the time segment is derived. An approximation of the estimate is derived by smoothing the estimate, and a frequency mask is derived by inverting the approximation. An emphasized damping is assigned to the frequency mask in a predefined frequency range, as compared to the damping outside the predefined frequency range. Frequencies comprised in the audio time segment are then damped based on the frequency mask. The method and arrangement involves no multi-band filtering or selection of attack and release times.

Abstract: Disclosed herein are systems, methods, and non-transitory computer-readable storage media for automatically analyzing, modifying, and mixing a plurality of audio signals. The modification of the audio signals takes place to avoid spectral collisions which occur when more than one signal simultaneously occupies one or more of the same frequency bands. The modifications mask out some signals to allow others to exist unaffected. Also disclosed herein is a method for displaying the identified spectral collisions superimposed on graphical waveform representations of the analyzed signals.

Abstract: In a masking sound generation apparatus, a CPU analyzes a speech utterance speed of a received sound signal. Then, the CPU copies the received sound signal into a plurality of sound signals and performs the following processing on each of the sound signals. Namely, the CPU divides each of the sound signals into frames on the basis of a frame length determined on the basis of the speech utterance speed. Reverse process is performed on each of the frames to replace a waveform of the frame with a reverse waveform, and a windowing process is performed to achieve a smooth connection between the frames. Then, the CPU randomly rearranges the order of the frames and mixes the plurality of sound signals to generate a masking sound signal.

Abstract: An engine sound control apparatus capable of arranging a sound of a frequency that is lower than the fundamental-order frequency of the engine. The engine sound control apparatus detects the frequency of the engine sound and generates a sound signal of a frequency that is in accordance with a control signal and outputting the sound signal generated by the oscillator. Through the interaction between the sound generated by the apparatus and the engine sound, occupants in the passenger compartment will perceive a sound of a frequency that is equal to the difference between the generated sound and the fundamental-order sound. This yields a sound that is lower in frequency than the fundamental-order sound without actually generating a sound of a frequency that is lower than that of the fundamental-order sound.

Abstract: Methods and systems for masking audio noise are disclosed. One apparatus includes a silence detector configured to detect a period of substantial silence in an audio signal; a masking noise source operably coupled to the silence detector, the masking noise source configured to generate a noise signal in response to the silence detector detecting the period of substantial silence; and at least one combining device operably coupled to the masking noise source, the at least one combining device configured to contribute to combining the audio signal and the noise signal. A method includes detecting a period of substantial silence in an audio signal; and combining masking noise with the audio signal during the period of substantial silence.

Abstract: A method for processing an input signal to create an enhanced output signal includes obtaining an envelope of the input signal, determining a logarithm signal of the envelope, determining a rate of change of the logarithm signal to obtain a slope value, and applying a value derived from the slope value to the input signal to thereby generate an enhanced output signal.

Abstract: A handheld foldable voice-muffling device using passive noise silencing materials to dampen noise and a microphonic transceiver to transmit a user's speech and receive incoming signals allowing him to wirelessly communicate with another person or other communication devices without causing a disturbance to others in his surrounding area.

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: Wind and other noise is suppressed in a signal by adaptively changing characteristics of a filter. The filter characteristics are changed in response to the noise content of the signal over time using a history of noise content. Filter characteristics are changed according to a plurality of reference filters, the characteristics of which are chosen to optimally attenuate or amplify signals in a range of frequencies.

Abstract: A conversation shielding system comprises sensors that detect the location of a confidential conversation and the presence and location of a potential eavesdropper, audio output devices that produce masking sounds to shield the conversation from the eavesdropper, and a controller that automatically controls the operation of the output devices in response to data from the sensors. An optional portable controller may manually engage the system. A method for shielding conversation comprises identifying a conversation to be shielded, detecting a potential eavesdropper, automatically determining masking sound types, locations and volume that will shield the conversation, directing emission of masking sounds from at least one audio output device in order to shield the conversation, including adjusting the masking sound type, location, and volume in response to movement of the conversation or the eavesdropper, and continuing to shield the conversation until it ends or the eavesdropper is no longer detected.

Abstract: A method, medium, and apparatus for extracting a target sound from mixed sound. The method includes receiving a mixed signal through a microphone array, generating a first signal whose directivity is emphasized toward a target sound source and a second signal whose directivity toward the target sound source is suppressed based on the mixed signal, and extracting a target sound signal from the first signal by masking an interference sound signal, which is contained in the first signal, based on a ratio of the first signal to the second signal. Therefore, a target sound signal can be clearly separated from a mixed sound signal which contains a plurality of sound signals and is input to a microphone array.

Abstract: A method and system for masking pure tones within sound generated from a noise generating source. The method includes detecting one or more pure tones within sound being generated from the noise generating source, and generating one or more masking sounds capable of masking only the one or more pure tones detected within the sound.

Abstract: An engine harmonic enhancement system. The EHE system uses multiple parameters, such as engine load, gear, number of cylinders operating, and transmission ratio, to determine EHE gains to determine EHE gain. The EHE system determines a separate EHE gain for each harmonic.

Abstract: Interfering signals that may be present in a listening environment are masked by reproducing a desired signal in a listening environment, determining a masking threshold associated with the desired signal, identifying an interfering signal that may be present in the environment, comparing the interfering signal to the masking threshold, and adjusting the desired signal over time to raise its masking threshold above the level of the interfering signal.

Abstract: An audio processing apparatus includes a first microphone, a second microphone, and a masking unit configured to mask movement of air from outside of the apparatus to the second microphone. A filter coefficient is estimated and learned so as to minimize the difference between the output signal of the first microphone and the output signal of the second microphone, thereby suppressing a reverberation component generated in the closed space between the masking unit and the second microphone out of the output signal of the second microphone.

Abstract: An active control of an unwanted noise signal at a listening site radiated by a noise source uses a reference signal that has an amplitude and/or frequency such that it is masked for a human listener at the listening site by the unwanted noise signal and/or a wanted signal present at the listening site in order to adapt for the time-varying secondary path in a real time manner such that a user doesn't feel disturbed by an additional artificial noise source.

Abstract: A sound monitoring system and method. The system can include a plurality of sound pressure level meters, a plurality of sound level indicators and a server connected by a network. The sound pressure level meters measuring a sound level at their location, and the sound level indicators providing a visual indication of the sound level measured by at least one of the sound pressure level meters. The system devices can be powered, as well as monitored and controlled remotely over the network. A user interface enables constructing and monitoring multiple zones and groups in a monitored area, as well as reviewing real-time and historical sound data. The system can also control lighting in the monitored area, and use lighting as a visual indicator of noise level.

Abstract: A system and method are provided for smoothing the in-room acoustic magnitude response of an audio reproduction system. An in-room acoustic magnitude response analysis is performed to determine a room resonance induced peak associated with an audio signal. A replica of the audio signal is filtered at the room resonance induced peak. The filtered replica signal is added with the audio signal. Through this, smoothing of the room resonance induced peak may be achieved, such that a subjective impression of transient response and dynamics of the audio signal are preserved.

Abstract: A system and method for providing call privacy for a wireless communication device. A voice communication is received from a user. The voice communication is processed to determine a response signal in response to receiving the voice signal. The response signal is broadcast about the periphery of the user as the voice input is received. The response signal is operative to cause the voice communication to be less discernible by one or more bystanders.

Abstract: An improved power amplifier system is provided. The power amplifier system includes a programmable digital filter and a power amplifier, each responsive to a plurality of frequency response settings and switching frequency settings, respectively. Each frequency response setting and switching frequency setting is adaptively selected by a processor device to match a bandwidth of an incoming audio signal. The processor device identifies the current bandwidth of an incoming audio signal and adaptively selects a switching rate setting and a frequency response setting based on the current bandwidth. The frequency response setting is selected so as to reduce noise fold over in the power amplifier for a corresponding bandwidth, sampling rate setting, and switching frequency setting.

Abstract: Systems and methods for providing voice equalization are provided. In exemplary embodiments, acoustic signals are received from both a near-end and a far-end environment. A power spectrum estimate for the far-end signal and a noise estimate based on the near-end signal are determined. A voice equalization mask based on the power spectrum estimate of the far-end signal and the noise estimate based on the near-end signal is generated and applied to the far-end signal to obtain a modified signal. The modified signal may then be dynamically processed to obtain an enhanced audio signal. The enhanced audio signal is then output.

Abstract: A cognitive load reduction system comprises a sound source position decision engine configured to receive one or more audio signals from a corresponding one or more signal generators, wherein the sound source position decision engine is further configured to identify two or more discrete sound sources within at least one of the one or more audio signals. The cognitive load reduction system further comprises an environmental assessment engine configured to assess environmental sounds within an environment. The cognitive load reduction system further comprises a sound location engine configured to output one or more audio signals configured to cause a plurality of speakers to change a perceived location of at least one of the discrete sound sources within the environment responsive to locations of other sounds within the environment.

Abstract: This specification describes technologies relating to reducing audio masking. In general, one aspect of the subject matter described in this specification can be embodied in methods that include the actions of receiving a primary audio signal and a secondary audio signal; for each audio signal, calculating an average perceived intensity over time for each of a plurality of frequency bands; comparing the average perceived intensity of the secondary audio signal with the average perceived intensity of the primary audio signal for each frequency band; and for each frequency band where the average perceived intensity of the secondary audio signal is greater than the average perceived intensity of the primary audio signal by a specified threshold amount, attenuating the secondary audio signal by a specified amount to form a modified secondary audio signal.

Abstract: An audio output apparatus includes a masking band determining unit configured to determine a first frequency band in which masking due to environmental sounds is likely to occur in audio signal output sounds; a band-component extracting unit configured to extract a signal component from an input audio signal in the first frequency band determined by the masking band determining unit; a pitch shift unit configured to perform pitch shifting of the signal component in the first frequency band extracted by the band-component extracting unit and generate a pitch shift signal containing a signal component of at least a doubled frequency; and a signal output unit configured to supply an audio signal containing the pitch shift signal acquired by the pitch shift unit to a connected speaker.

Abstract: Noise discrimination in signals from a plurality of sensors is conducted by enhancing the phase difference in the signals such that off-axis pick-up is suppressed while on-axis pick-up is enhanced. Alternatively, attenuation/expansion are applied to the signals in a phase difference dependent manner, consistent with suppression of off-axis pick-up and on-axis enhancement. Nulls between sensitivity lobes are widened, effectively narrowing the sensitivity lobes and improving directionality and noise discrimination.

Abstract: A noise injection system adds comfort noise to an audio signal. The system includes a background noise estimator that determines a spectral content of a background noise associated with the audio signal. A comfort noise generator generates a comfort noise signal having a random phase. A gain circuit adjusts the comfort noise signal based on the spectral content of the background noise. A combining circuit combines a gain-adjusted comfort noise signal and the audio signal to generate an output signal.

Abstract: A manually switching dual-mode hearing protector including an active hearing protection device that does not only provide for acoustic attenuation of ambient sound in order to protect hearing of a user in a noisy environment but in addition provides electro-acoustically bypassing of this acoustic attenuation function in order to provide the user with a communication function in order to enable the user to perceive speech signals even when wearing the manually switching dual-mode hearing protector in a noisy environment.

Abstract: Speakers deployed in a space and divided into groups associated with different zones produce a mix of sounds that create internal noise pollution and, combined with external noise, an unpleasant environment for occupants. The present invention contemplates sound systems and methods for creating personalized sound zones to address these and related problems.

Abstract: A tracking system may determine the orientation or position of a movable object. The tracking system includes a signal generator that generates a non-audible detection signal in an audible frequency range. A transmitting device transmits the detection signal to a detection device. The transmitting device or the detection device may be positioned on the movable object, and the other may be positioned at a remote location. A processor may determine an orientation or position of the moveable object based on the transmission time between the transmitting device and the detection device.

Abstract: A sound masking system and method for providing sound masking in networked workstations or offices. The sound masking system comprises a communication network, a plurality of sound masking devices adapted to emit a sound masking signal, and a remote controller. One or more of the sound masking devices includes a controller, and the controller includes an interface for receiving information from the communication network and a component for controlling or adjusting output characteristics associated with the sound masking signal, such as volume. The controller includes a component responsive to a user input for setting or varying output characteristics associated with the sound masking signal.

Abstract: Masking thresholds are obtained for each frequency component of sound data and ambient noise. It is determined whether each frequency component of the sound data is masked by at least one of the other frequency components of the sound data. It is further determined whether each frequency component of the sound data is masked by ambient noise. Correction coefficients are set for each frequency component of the sound data according to whether the frequency component is masked by at least one of the other frequency components of the sound data and whether the frequency component is masked by the ambient noise. And each frequency component of the sound data is corrected by using the respective correction coefficients.

Abstract: A grounding switch is described which operates properly even in the presence of negative voltages on a signal line. The grounding switch uses isolated field effect transistors that have their substrates tied to different voltages. The isolated field effect transistor has a gate voltage and substrate voltage which can be pulled down to a negative voltage when the signal line has a negative voltage allowing the switch to remain open even with a negative voltage.

Abstract: The subject matter of this specification can be embodied in, among other things, a computer-implemented method for removing noise from audio that includes building a sound model that represents noises which result from activations of input controls of a computer device. The method further includes receiving an audio signal produced from a microphone substantially near the computer device. The method further includes identifying, without using the microphone, an activation of at least one input control from among the input controls. The method further includes associating a portion of the audio signal as corresponding to the identified activation. The method further includes applying, from the audio model, a representation of a noise for the identified activation to the associated portion of the audio signal so as to cancel at least part of the noise from the audio signal.

Abstract: An aural device to be worn over the ear of a user during sleeping hours which generates white noise.

Abstract: Provided is a method and system for audio privacy that includes receiving a first sound signal at a microphone proximal to a user's ear, generating a second sound signal based on the first sound signal and a stored filter, the second sound signal interfering with the first sound signal, and emitting the second sound signal from a speaker proximal to the user's ear.

Abstract: In a masking sound generation apparatus, a CPU analyzes a speech utterance speed of a received sound signal. Then, the CPU copies the received sound signal into a plurality of sound signals and performs the following processing on each of the sound signals. Namely, the CPU divides each of the sound signals into frames on the basis of a frame length determined on the basis of the speech utterance speed. Reverse process is performed on each of the frames to replace a waveform of the frame with a reverse waveform, and a windowing process is performed to achieve a smooth connection between the frames. Then, the CPU randomly rearranges the order of the frames and mixes the plurality of sound signals to generate a masking sound signal.

Abstract: A method and device for tinnitus therapy. The method includes generating pure sounds, each having a predetermined frequency, within an audible range, and waiting for a user to press an input button when the user hears the pure sound. Then, the hearing characteristics of the user are interpreted in conjunction with equal loudness contours. From this interpretation, either a tinnitus masking method or a tinnitus retraining therapy are selected according to the hearing characteristics of the user.

Abstract: A method for protecting a data entry device from eavesdropping includes masking a signature of entry resulting from entry of data by a user of the data entry device so as to reduce the detectability of the signature by eavesdropping. The signature may include a temperature differential in the data entry device from data entry by the user and the masking may include controlling the external temperature of the data entry device to reduce temperature differentials left in the data entry device by the user. Alternatively, the signature may include sound waves emitted from the data entry device and the masking may include masking sound waves emitted from the data entry device to reduce the detectability of the sound waves. A system may also be employed for protecting data entry to a data entry device from eavesdropping.