Abstract: An audio system, method, and computer program product which includes a wearable audio device and a peripheral device. Each device is capable of determining its respective absolute or relative position and orientation. Once the relative positions and orientations between the devices are known, virtual sound sources are generated at fixed positions and orientations relative to the peripheral device such that any change in position and/or orientation of the peripheral device produces a proportional change in the position and/or orientation of the virtual sound sources. Additionally, first order and second order reflected audio paths may be simulated for each virtual sound source to increase the realism of the simulated sources. Each sound path can be produced by modifying the original audio signal using head-related transfer functions (HRTFs) to simulate audio as though it were perceived by the user's left and right ears as coming from each virtual sound source.

Abstract: A noise reduction system includes sensors configured to generate an input signal, an adaptive filter configured to represent a transfer function of a path traversed by the input signal, one or more processing devices, and one or more transducers. The processing devices receive the input signal and generate an updated set of filter coefficients of the adaptive filter by separating the input signal into frequency subbands; determining for each subband, coefficients of a corresponding subband adaptive module; and combining the coefficients of multiple subband adaptive modules. Determining the coefficients of the corresponding subband adaptive module includes selecting a subset of a precomputed set of filter coefficients of the adaptive filter. The processing devices process a portion of the input signal using the updated set of filter coefficients of the adaptive filter to generate an output that destructively interferes with another signal traversing the path represented by the transfer function.

Abstract: A system and method for externalizing sound. The system includes a headphone assembly and a localizer configured to collect information related to a location of the user and of an acoustically reflective surface in the environment. A controller is configured to determine a location of at least one virtual sound source, and generate head related transfer functions that simulate characteristics of sound from the virtual sound source directly to the user and to the user via a reflection by the reflective surface. A signal processing assembly is configured to create one or more output signals by filtering the sound signal respectively with the HRTFs. Each speaker of the headphone assembly is configured to produce sound in accordance with the output signal.

Abstract: A system and method for externalizing sound. The system includes a headphone assembly and a localizer configured to collect information related to a location of the user and of an acoustically reflective surface in the environment. A controller is configured to determine a location of at least one virtual sound source, and generate head related transfer functions that simulate characteristics of sound from the virtual sound source directly to the user and to the user via a reflection by the reflective surface. A signal processing assembly is configured to create one or more output signals by filtering the sound signal respectively with the HRTFs. Each speaker of the headphone assembly is configured to produce sound in accordance with the output signal.

Abstract: An audio system, method, and computer program product which includes a wearable audio device and a peripheral device. Each device is capable of determining its respective absolute or relative position and orientation. Once the relative positions and orientations between the devices are known, virtual sound sources are generated at fixed positions and orientations relative to the peripheral device such that any change in position and/or orientation of the peripheral device produces a proportional change in the position and/or orientation of the virtual sound sources. Additionally, first order and second order reflected audio paths may be simulated for each virtual sound source to increase the realism of the simulated sources. Each sound path can be produced by modifying the original audio signal using head-related transfer functions (HRTFs) to simulate audio as though it were perceived by the user's left and right ears as coming from each virtual sound source.

Abstract: An audio enhancement method includes receiving a first plurality of input signals representative of audio captured using an array of two or more sensors, the first plurality of input signals characterized by a first signal-to-noise ratio (SNR), with the audio being the signal-of-interest. The method also includes receiving a second input signal representative of the audio, the second input signal characterized by a second SNR. The second SNR is higher than the first SNR. The method further includes combining the first plurality of input signals and the second input signal to generate one or more driver signals, and driving one or more acoustic transducers using the one or more driver signals to generate an acoustic signal representative of the audio. The driver signals include spatial information derived from the first plurality of input signals, and are characterized by a third SNR that is higher than the first SNR.

Abstract: An audio system, method, and computer program product which includes a wearable audio device and a mobile peripheral device. Each device is capable of determining its respective absolute or relative position and orientation. Once the relative positions and orientations between the devices are known, virtual sound sources are generated at fixed positions and orientations relative to the peripheral device such that any change in position and/or orientation of the peripheral device produces a proportional change in the position and/or orientation of the virtual sound sources. Additionally, first order and second order reflected audio paths may be simulated for each virtual sound source to increase the realism of the simulated sources. Each sound path can be produced by modifying the original audio signal using head-related transfer functions (HRTFs) to simulate audio as though it were perceived by the user's left and right ears as coming from each virtual sound source.

Abstract: An audio system, method, and computer program product which includes a wearable audio device and a mobile peripheral device. Each device is capable of determining its respective absolute or relative position and orientation. Once the relative positions and orientations between the devices are known, virtual sound sources are generated at fixed positions and orientations relative to the peripheral device such that any change in position and/or orientation of the peripheral device produces a proportional change in the position and/or orientation of the virtual sound sources. Additionally, first order and second order reflected audio paths may be simulated for each virtual sound source to increase the realism of the simulated sources. Each sound path can be produced by modifying the original audio signal using head-related transfer functions (HRTFs) to simulate audio as though it were perceived by the user's left and right ears as coming from each virtual sound source.

Abstract: A system and method for determining the position and orientation of a wearable audio device, for example, methods and systems for determining the position, orientation, and/or height of a wearable audio device using acoustic beacons. In some examples, the determined position, orientation, and/or height can be utilized to correct for drift experienced by an inertial measurement unit (IMU). In other examples, the drift may cause am externalized or virtualize audio source, generated within a known environment, to move or drift relative to the known locations of physical audio sources within the environment. Thus, the systems and methods described herein can be utilized to correct for drift in the position of a virtual audio source with respect to the wearable audio device by first determining its own absolute position and orientation within the environment.

Abstract: An audio system, method, and computer program product which includes a wearable audio device and a mobile peripheral device. Each device is capable of determining its respective absolute or relative position and orientation. Once the relative positions and orientations between the devices are known, virtual sound sources are generated at fixed positions and orientations relative to the peripheral device such that any change in position and/or orientation of the peripheral device produces a proportional change in the position and/or orientation of the virtual sound sources. Additionally, first order and second order reflected audio paths may be simulated for each virtual sound source to increase the realism of the simulated sources. Each sound path can be produced by modifying the original audio signal using head-related transfer functions (HRTFs) to simulate audio as though it were perceived by the user's left and right ears as coming from each virtual sound source.

Abstract: A noise reduction system includes sensors configured to generate an input signal, an adaptive filter configured to represent a transfer function of a path traversed by the input signal, one or more processing devices, and one or more transducers. The processing devices receive the input signal and generate an updated set of filter coefficients of the adaptive filter by separating the input signal into frequency subbands; determining for each subband, coefficients of a corresponding subband adaptive module; and combining the coefficients of multiple subband adaptive modules. Determining the coefficients of the corresponding subband adaptive module includes selecting a subset of a precomputed set of filter coefficients of the adaptive filter. The processing devices process a portion of the input signal using the updated set of filter coefficients of the adaptive filter to generate an output that destructively interferes with another signal traversing the path represented by the transfer function.

Abstract: An audio enhancement method includes receiving a first plurality of input signals representative of audio captured using an array of two or more sensors, the first plurality of input signals characterized by a first signal-to-noise ratio (SNR), with the audio being the signal-of-interest. The method also includes receiving a second input signal representative of the audio, the second input signal characterized by a second SNR. The second SNR is higher than the first SNR. The method further includes combining the first plurality of input signals and the second input signal to generate one or more driver signals, and driving one or more acoustic transducers using the one or more driver signals to generate an acoustic signal representative of the audio. The driver signals include spatial information derived from the first plurality of input signals, and are characterized by a third SNR that is higher than the first SNR.

Abstract: A noise reduction system includes sensors configured to generate an input signal, an adaptive filter configured to represent a transfer function of a path traversed by the input signal, one or more processing devices, and one or more transducers. The processing devices receive the input signal and generate an updated set of filter coefficients of the adaptive filter by separating the input signal into frequency subbands; determining for each subband, coefficients of a corresponding subband adaptive module; and combining the coefficients of multiple subband adaptive modules. Determining the coefficients of the corresponding subband adaptive module includes selecting a subset of a precomputed set of filter coefficients of the adaptive filter. The processing devices process a portion of the input signal using the updated set of filter coefficients of the adaptive filter to generate an output that destructively interferes with another signal traversing the path represented by the transfer function.

Abstract: A noise reduction system includes sensors configured to generate an input signal, an adaptive filter configured to represent a transfer function of a path traversed by the input signal, one or more processing devices, and one or more transducers. The processing devices receive the input signal and generate an updated set of filter coefficients of the adaptive filter by separating the input signal into frequency subbands; determining for each subband, coefficients of a corresponding subband adaptive module; and combining the coefficients of multiple subband adaptive modules. Determining the coefficients of the corresponding subband adaptive module includes selecting a subset of a precomputed set of filter coefficients of the adaptive filter. The processing devices process a portion of the input signal using the updated set of filter coefficients of the adaptive filter to generate an output that destructively interferes with another signal traversing the path represented by the transfer function.

Abstract: The technology described this document can be embodied in a method that includes receiving an error signal captured using a microphone, the error signal representing a difference between the sinusoidal component of a noise signal and an output of an acoustic transducer. The output of the acoustic transducer is configured to reduce the effects of the sinusoidal component of the noise signal. The method includes processing the error signal to compensate for effects due to a signal path between the acoustic transducer and the microphone, and determining a current estimate of one or more first parameters of the error signal. Based on such parameters, a current estimate of a time-varying step size associated with an adaptive process is determined, and based on the current estimate of the time-varying step size, a driver signal configured to change the output of the acoustic transducer is generated.

Abstract: A system for detecting divergence in a noise-cancellation system, comprising: a controller configured to: determine a power of a component of the error signal, the component being correlated to the at least one reference sensor signal; determine an average value, over a first time period, of a value representative of a time gradient of the power of the component of the error signal; and determine whether the average value is greater than a threshold.

Abstract: A system and method for externalizing sound. The system includes a headphone assembly and a localizer configured to collect information related to a location of the user and of an acoustically reflective surface in the environment. A controller is configured to determine a location of at least one virtual sound source, and generate head related transfer functions that simulate characteristics of sound from the virtual sound source directly to the user and to the user via a reflection by the reflective surface. A signal processing assembly is configured to create one or more output signals by filtering the sound signal respectively with the HRTFs. Each speaker of the headphone assembly is configured to produce sound in accordance with the output signal.

Abstract: A system and method for externalizing sound. The system includes a headphone assembly and a localizer configured to collect information related to a location of the user and of an acoustically reflective surface in the environment. A controller is configured to determine a location of a virtual sound source, and generate head related transfer functions that simulate characteristics of sound from the virtual sound source directly to the user and to the user via a reflection by the reflective surface. A signal processing assembly is configured to create one or more output signals by filtering the sound signal respectively with the HRTFs. Each speaker of the headphone assembly is configured to produce sound in accordance with the output signal.

Abstract: The technology described this document can be embodied in a method that includes receiving an error signal captured using a microphone, the error signal representing a difference between the sinusoidal component of a noise signal and an output of an acoustic transducer. The output of the acoustic transducer is configured to reduce the effects of the sinusoidal component of the noise signal. The method includes processing the error signal to compensate for effects due to a signal path between the acoustic transducer and the microphone, and determining a current estimate of one or more first parameters of the error signal. Based on such parameters, a current estimate of a time-varying step size associated with an adaptive process is determined, and based on the current estimate of the time-varying step size, a driver signal configured to change the output of the acoustic transducer is generated.

Abstract: A method and system for a noise cancellation comprises an amplifier in communication with three or more speakers disposed in an area. A system controller produces a driver signal for each of the speakers in response to a signal from at least one microphone detecting sound in the area and communicates the driver signals to the amplifier. The amplifier drives each speaker with the driver signal produced for that speaker. In response to the driver signals, the speakers emit sound having a magnitude and phase that combine to attenuate a noise field in the area.