Abstract: An electrostatic transducer including a membrane, a first electrode and a second electrode. The first electrode is disposed parallel to the membrane. The membrane is configured to respond mechanically to a varying first electric field in accordance with respective electric potentials applied between the first electrode and the membrane. The second electrode is disposed parallel to the membrane opposite from the first electrode. The membrane is configured to respond mechanically to a varying second electric field in accordance with respective electric potentials between the second electrode and the membrane. The first and second electrodes have through holes configured for acoustic transmission to and from the membrane.

Abstract: A trained machine configured to input a stereo sound track and separate the stereo sound track into multiple N separated stereo audio signals respectively characterized by multiple N audio content classes. All stereo audio as input in the stereo sound track is included in the N separated stereo audio signals. A mixing module is configured to spatially localize symmetrically and without cross-talk, between left and right, the N separated stereo audio signals into multiple output channels. The output channels include respective mixtures of one or more of the N separated stereo audio signals. Gain is adjusted of the output channels into left and right binaural outputs to conserve summed levels of the N separated stereo audio signals distributed over the output channels.

Abstract: A control circuit for an electrostatic transducer including: an audio signal input, a detector configured to detect a current or charge signal from the electrostatic transducer. The detector is configured to produce an audio output signal varying at audio frequencies. A transform circuit is configured to transform the audio output signal to produce a feedback signal. A comparator is configured to compare an input audio signal at the audio signal input to the feedback signal to produce an error signal. A controller is configured to input a control signal to the electrostatic transducer, the control signal responsive to the error signal. The control signal is configured to control acoustic transparency of the electrostatic transducer, from outside space through through-holes of the first electrode, across the membrane and through through-holes of the second electrode.

Abstract: A processor-based method of reducing loudspeaker-induced harmonic distortion in sound generated by a loudspeaker responsive to a first audio signal, the method including: attenuating a first band in the first audio signal by an attenuation gain, the first band including a fundamental frequency, wherein the attenuating dynamically adjusts the attenuation gain in accordance with, at least, a ratio between: i) an energy of the first band in the first audio signal; and ii) an energy of a second band in the first audio signal, the second band including one or more frequencies that is an integer multiple of the fundamental frequency.

Abstract: An audio system including a first microphone-equipped playback device and a second microphone-equipped playback device. The audio system is configured to synchronize playing of audio to a listener position by receiving by the first microphone-equipped playback device an audio stream, and playing the audio stream on a speaker of the first microphone-equipped playback device, in accordance with a playback delay ?t. The playback delay ?t is in accordance with a first calibration sound originating at the listening position, a second calibration sound originating at the second microphone-equipped playback device, and a third calibration sound originating at the first microphone-equipped playback device.

Abstract: Presentation of a recommendation to a user for individual processing of audio tracks in a digital audio workstation. Training audio tracks are provided to a human sound mixer and responsive to the training audio tracks individually processed training audio tracks are received from the human sound mixer. The training audio tracks and the individually processed training audio tracks are input to a machine to train the machine. Audio processing operations are output from the trained machine and stored in a record of a database.

Abstract: Controlling temperature of a surface of the electronic device. The electronic device includes: a speaker, an adaptive control circuit configured to receive an audio input signal responsive to an audio input power to the speaker and a temperature sensor configured to sense a temperature internal to the electronic device. A temperature signal responsive to the sensed temperature is input to the adaptive control circuit. Responsive to the audio input signal and the temperature signal a power control signal is computed by the adaptive control circuit so that a temperature of the surface of the electronic device at a later time approaches a previously determined target temperature. An audio limiter is configured to limit the audio input power to the speaker responsive to the power control signal.

Abstract: Computing a relative-head-orientation relative to a moving-reference. First and second data are received. The first data are indicative of a head-orientation of a head of a user. The second data are indicative of at least one of: a location, a motion, an orientation, a velocity and an acceleration of the user. A head-orientation is computed according to the first data. A moving-reference is updated by an adjustment toward the head-orientation, to produce an updated-moving-reference. The amount of adjustment is indicated by processing the second data. A relative-head-orientation is computed relative to the updated-moving-reference. Binaural audio is rendered in accordance with the relative-head-orientation.

Abstract: Adjusting gains of an audio mix. Audio tracks using respective gains are individually analyzed to compute a first metric of frequency content. A user input specifies a desired second metric of the frequency content. Responsive to the user input, respective gains of the audio tracks are collectively and simultaneously adjusted to produce respective adjusted gains of the audio tracks. A second audio mix when played of the audio tracks with the respective adjusted gains has a third metric of frequency content different from the first metric of frequency content. The third metric is closer to the second metric than said first metric.

Abstract: An audio system including a first microphone-equipped playback device and a second microphone-equipped playback device. The audio system is configured to synchronize playing of audio to a listener position by receiving by the first microphone-equipped playback device an audio stream, and playing the audio stream on a speaker of the first microphone-equipped playback device, in accordance with a playback delay ?t. The playback delay ?t is in accordance with a first calibration sound originating at the listening position, a second calibration sound originating at the second microphone-equipped playback device, and a third calibration sound originating at the first microphone-equipped playback device.

Abstract: A computerized microphone-equipped audio playback device comprising a speaker and microphone and being configured to receive digital audio; and play the digital audio on a speaker, in accordance with a playback delay that is derivative of, at least: an arrival time of a first calibration sound at the processor and an arrival time of the first calibration sound at a second microphone-equipped audio playback device, wherein the first calibration sound originated at the listener position; a generation time of a second calibration sound at the second microphone-equipped audio playback device, and an arrival time of the second calibration sound at the processor; and a generation time of a third calibration sound at the processor, and an arrival time of the third calibration sound at the second microphone-equipped audio playback device; thereby synchronizing arrival of sound of the two playback devices at the listener position.

Abstract: A processor-based method of reducing loudspeaker-induced harmonic distortion in sound generated by a loudspeaker responsive to a first audio signal, the method including: attenuating a first band in the first audio signal by an attenuation gain, the first band including a fundamental frequency, wherein the attenuating dynamically adjusts the attenuation gain in accordance with, at least, a ratio between: i) an energy of the first band in the first audio signal; and ii) an energy of a second band in the first audio signal, the second band including one or more frequencies that is an integer multiple of the fundamental frequency.

Abstract: First and second computer systems and respective first and second microphones thereof receive respective portions of a same audio input signal. Audio buffers received respectively from the first and second computer system include data encoded from respective microphone inputs of the first and the second computer systems. The received audio buffers are synchronized and corrected for gain differences between the received audio buffers to produce corrected audio buffers. The corrected audio buffers are mixed into an output buffer. The synchronization reduces echo when the output buffer is played at a remote peer computer system.

Abstract: Controlling temperature of a surface of the electronic device. The electronic device includes: a speaker, an adaptive control circuit configured to receive an audio input signal responsive to an audio input power to the speaker and a temperature sensor configured to sense a temperature internal to the electronic device. A temperature signal responsive to the sensed temperature is input to the adaptive control circuit. Responsive to the audio input signal and the temperature signal a power control signal is computed by the adaptive control circuit so that a temperature of the surface of the electronic device at a later time approaches a previously determined target temperature. An audio limiter is configured to limit the audio input power to the speaker responsive to the power control signal.

Abstract: A method and system of providing an adaptive reference orientation usable for determining a relative head orientation of a user, the method being implemented by a processing unit and comprising: repeatedly providing: receiving first data sensed by one or more sensors, said first data being indicative of a user's head orientation; obtaining a new adaptive reference orientation by moving a current adaptive reference orientation at least partly towards said indicated head orientation, by an amount which is varied at least partly in accordance with second data, said second data having been sensed by one or more sensors and being indicative of changes of a current frame of reference of the user; computing head orientation relative to said adaptive reference orientation; and using said new adaptive reference orientation as a current adaptive reference orientation for a next repeat of operations.

Abstract: A method for conveying to a listener a directionality-preserving pseudo low frequency psycho-acoustic sensation of a multichannel sound signal, including: deriving from the sound signal, by a processing unit, a high frequency multichannel signal and a low frequency multichannel signal, generating a multichannel harmonic signal, the loudness of at least one channel signal of the multichannel harmonic signal substantially matching the loudness of a corresponding channel in the low frequency multichannel signal; and at least one interaural level difference (ILD) of at least one frequency of the at least one channel pair of the multichannel harmonic signal substantially matching an ILD of a corresponding fundamental frequency in a corresponding channel pair in the low frequency multichannel signal; and summing the harmonic multichannel signal and the high frequency multichannel signal thereby giving rise to a psychoacoustic alternative signal.

Abstract: A computerized microphone-equipped audio playback device comprising a speaker and microphone and being configured to receive digital audio; and play the digital audio on a speaker, in accordance with a playback delay that is derivative of, at least: an arrival time of a first calibration sound at the processor and an arrival time of the first calibration sound at a second microphone-equipped audio playback device, wherein the first calibration sound originated at the listener position; a generation time of a second calibration sound at the second microphone-equipped audio playback device, and an arrival time of the second calibration sound at the processor; and a generation time of a third calibration sound at the processor, and an arrival time of the third calibration sound at the second microphone-equipped audio playback device; thereby synchronizing arrival of sound of the two playback devices at the listener position.

Abstract: A membrane hetero-structure includes a polymer layer and a single-layer or multi-layer graphene sheet disposed on the polymer layer. The membrane hetero-structure is tensioned across a frame having an opening such that both the polymer layer and the graphene sheet extend across the opening. An optional rigid member is provided in a center of the membrane to be spaced apart from edges of the opening. The assembly of the frame and membrane hetero-structure forms an electrostatically driven micro-electro-mechanical system (MEMS) or sound generation and recording apparatus. In one instance, when a voltage signal is applied between an electrode layer parallel to the membrane and contacts on the frame that are electrically connected to the graphene sheet, the membrane hetero-structure is actuated.

Abstract: A method and system for providing head orientation relative to an adaptive reference orientation, implemented by a processing unit and comprising receiving head data from a head sensor, said head data describing a first head orientation of a user; receiving second data from a second sensor; adapting said adaptive reference orientation by moving it at least partly towards said first head orientation by an amount which is varied at least partly in accordance with said second data, thereby generating a new adaptive reference orientation; and generating, in accordance with said first head orientation and said new adaptive reference orientation, a second head orientation of the user as said first head orientation relative to said new adaptive reference orientation.

Abstract: A method for conveying to a listener a directionality-preserving pseudo low frequency psycho-acoustic sensation of a multichannel sound signal, including: deriving from the sound signal, by a processing unit, a high frequency multichannel signal and a low frequency multichannel signal, generating a multichannel harmonic signal, the loudness of at least one channel signal of the multichannel harmonic signal substantially matching the loudness of a corresponding channel in the low frequency multichannel signal; and at least one interaural level difference (ILD) of at least one frequency of the at least one channel pair of the multichannel harmonic signal substantially matching an ILD of a corresponding fundamental frequency in a corresponding channel pair in the low frequency multichannel signal; and summing the harmonic multichannel signal and the high frequency multichannel signal thereby giving rise to a psychoacoustic alternative signal.