Abstract: Systems and methods discussed herein can change a frame of reference for a first spatial audio signal. The first spatial audio signal can include signal components representing audio information from different depths or directions relative to an audio capture location associated with an audio capture source device with a first frame of reference relative to an environment Changing the frame of reference can include receiving a component of the first spatial audio signal, receiving information about a second frame of reference relative to the same environment, determining a difference between the first and second frames of reference, and, using the determined difference between the first and second frames of reference, determining a first filter to use to generate at least one component of a second spatial audio signal that is based on the first spatial audio signal and is referenced to the second frame of reference.

Abstract: Embodiments of systems and methods for user enrollment in speaker authentication and speaker identification systems are disclosed. In some embodiments, the enrollment process includes collecting speech samples that are examples of multiple speech types spoken by a user, computing a speech representation for each speech sample, and aggregating the example speech representations to form a robust overall representation or user voiceprint of the user's speech.

Abstract: A multi-factor identification system is provided in which enrolled user authentication information is updated in the course of an authorization request based upon at least one of a confidence level of a match between a request first factor identifier, produced based upon first unique user identifying information received with the authentication request, and a respective matching enrolled first factor identifier and a confidence level of a match between a request second factor identifier, produced based upon second unique user identifying information received with the authentication request, and a respective matching enrolled second factor identifier.

Abstract: An audio signal encoding method is provided comprising: receiving first and second audio signal frames; processing a second portion of the first audio signal frame and a first portion of the second audio signal frame using an orthogonal transformation to determine in part a first intermediate encoding result; and processing the first intermediate encoding result using an orthogonal transformation to determine a set of spectral coefficients that corresponds to at least a portion of the first audio signal frame.

Abstract: A method of encoding an audio signal is provided comprising: applying multiple different time-frequency transformations to an audio signal frame; computing measures of coding efficiency across multiple frequency bands for multiple time-frequency resolutions; selecting a combination of time-frequency resolutions to represent the frame at each of the multiple frequency bands based at least in part upon the computed measures of coding efficiency; determining a window size and a corresponding transform size; determining a modification transformation; windowing the frame using the determined window size; transforming the windowed frame using the determined transform size; modifying a time-frequency resolution within a frequency band of the transform of the windowed frame using the determined modification transformation.

Abstract: Embodiments of systems and methods are described for estimating a position of a loudspeaker and notifying a listener if an abnormal condition is detected, such as an incorrect loudspeaker orientation or an obstruction in a path between the loudspeaker and a microphone array. For example, a front component of a multi-channel surround sound system may include the microphone array and a position estimation engine. The position estimation engine may estimate the distance between the loudspeaker and the microphone array. In addition, the position estimation engine may estimate an angle of the loudspeaker using a first technique. The position estimation engine may also estimate an angle of the loudspeaker using a second technique. The two angles can be processed to determine whether the abnormal condition exists. If the abnormal condition exists, a listener can be notified and be provided with suggestions for resolving the issue in a graphical user interface.

Abstract: A loudspeaker system can include a first loudspeaker driver provided in a substantially fixed spatial relationship relative to a microphone. The loudspeaker driver can be tuned, for example automatically and without user input. In an example, the tuning can include receiving transfer function reference information about the first loudspeaker driver and the microphone, and receiving information about a desired acoustic response for the loudspeaker system. The tuning can include determining a simulated response for the loudspeaker system using a first input signal and the transfer function reference information, and can include providing the first input signal to the first loudspeaker driver. In response to the first input signal, an actual response for the loudspeaker driver can be received using the microphone. A compensation filter can be determined for the loudspeaker system based on the determined simulated response and the received actual response for the loudspeaker system.

Abstract: In an audiovisual system, in which video is displayed on a screen that does not permit sound to pass through the screen, such as a light emitting diode panel, a high-frequency speaker positioned above an audience seating area can direct sound toward the screen, so that the screen can reflect the sound toward the audience seating area. The high-frequency speaker can be used with one or more low-frequency speakers positioned at or near the height of the audience seating area. The low-frequency and high-frequency sounds can appear to originate from close to the same height, thereby creating a realistic audio image at the audience seating area. A spectral filter can negate the spectral effects of propagation to and reflection from the screen. Suitable time delays can synchronize the high-frequency sound with the low-frequency sound and with video displayed on the screen.

Abstract: The directivity of a loudspeaker describes how sound produced by the speaker varies with angle and frequency. Low-frequency sound tends to be relatively omnidirectional, while high-frequency sound tends to be more strongly directional. Because the two ears of a listener are in different spatial positions, the direction-dependent performance of the speakers can produce unwanted differences in volume or spectral content between the two ears. For example, high-frequency sounds may appear to be muffled in one ear, compared to the other. A multi-speaker sound system can employ binaural directivity compensation, which can compensate for directional variations in performance of each speaker, and can reduce or eliminate the difference in volume or spectral content between the left and right ears of a listener. The binaural directivity compensation can optionally be included with spatial audio processing, such as crosstalk cancellation, or can optionally be included with loudspeaker equalization.

Abstract: A frequency domain long-term prediction system and method for estimating and applying an optimum long term predictor. Embodiments of the system and method include determining parameters of a single-tap predictor using a frequency-domain analysis having an optimality criteria based on spectral flatness measure. Embodiments of the system and method also include determining parameters of the long-term predictor by accounting for the performance of the vector quantizer in quantizing the various subbands. In some embodiments other encoder metrics (such as signal tonality) are used as well. Other embodiments of the system and method include determining the optimal parameters of the long-term predictor by accounting for some of the decoder operation. Other embodiments of the system and method include extending a 1-tap predictor to a k-th order predictor by convolving the 1-tap predictor with a pre-set filter and selecting from a table of such pre-set filters based on a minimum energy criteria.

Abstract: A method to decode audio signals is provided that includes: receiving an input spatial audio signal; determining directions of arrival of directional audio sources represented in the received input spatial audio signal; determining one of an active input spatial audio signal component and a passive spatial audio signal input component, based upon the determined directions of arrival; determining the other of the active input spatial audio signal component and the passive input spatial audio signal component based upon the determined one of the active input spatial audio signal component and the passive input spatial audio signal component; decoding the active input spatial audio signal component to a first output format; and decoding the passive input spatial audio signal component to a second output format.

Abstract: Systems and methods can provide an elevated, virtual loudspeaker source in a three-dimensional soundfield using loudspeakers in a horizontal plane. In an example, a processor circuit can receive at least one height audio signal that includes information intended for reproduction using a loudspeaker that is elevated relative to a listener, and optionally offset from the listener's facing direction by a specified azimuth angle. A first virtual height filter can be selected for use based on the specified azimuth angle. A virtualized audio signal can be generated by applying the first virtual height filter to the at least one height audio signal. When the virtualized audio signal is reproduced using one or more loudspeakers in the horizontal plane, the virtualized audio signal can be perceived by the listener as originating from an elevated loudspeaker source that corresponds to the azimuth angle.

Abstract: An air-cooled heat exchanger is provided. A reinforcement beam is laterally attached to an upper surface of a guide housing which is formed to have a dome shape having an area gradually increasing in a downward direction from the stack to guide air discharged to the stack. In another aspect, an air-cooled heat exchanger may further include an enclosure surrounding a power transmission part configured to transmit a rotation force of a motor to the fan to rotate the fan.

Abstract: A method to encode audio signals is provided for use with an audio capture device that includes multiple microphones having a spatial arrangement on the device, a method to encode audio signals comprising: receiving multiple microphone signals corresponding to the multiple microphones; determining a number and directions of arrival of directional audio sources represented in the one or more microphone signals; determining one of an active microphone signal component and a passive microphone signal component, based upon the determined number and directions of arrival; determining the other of the active microphone signal component and the passive microphone signal component, based upon the determined one of the active input spatial audio signal component and the passive input spatial audio signal component; encoding the active microphone signal component; encoding the passive microphone signal component.

Abstract: Embodiments of systems and methods are described for reducing undesired leakage energy produced by a non-front-facing speaker in a multi-speaker system. For example, the multi-speaker system can include an array of forward-facing speakers, one or more upward-facing speakers, and/or one or more side-facing speakers. Filters coupled to any two of the speakers in the multi-speaker system can generate audio signals output by the coupled speakers to reduce, attenuate, or cancel a portion of an audio signal output by one or more non-front-facing speakers that acoustically propagates along a direct path from the respective non-front-facing speaker to a listening position in a listening area in front of the multi-speaker system.

Abstract: Media is selected for video playback through a first device and audio playback through one or more separate devices connected through a wireless network. Different techniques for synchronizing the audio and video can be selected based on one or more factors to improve media playback.

Abstract: When the volume is adjusted in a multi-speaker system, it is desirable that one speaker does not change volume disproportionately with respect to another speaker. A method is presented for adjusting a volume level of one or more speakers. Each speaker can have a non-standardized relationship between logical volume level that is input to the speaker and sound pressure level that is produced by the speaker. A selected volume level, corresponding to a sound pressure level, can be received via a user interface. A stored lookup table can be accessed to convert the sound pressure level to a first product-specific logical volume level for each speaker. The stored lookup table can tabulate the non-standardized relationship between logical volume level and sound pressure level for each speaker. Data corresponding to the first product-specific logical volume level can be transmitted to each speaker.

Abstract: There are disclosed automatic mixers and methods for creating a surround audio mix. A set of rules may be stored in a rule base. A rule engine may select a subset of the set of rules based, at least in part, on metadata associated with a plurality of stems. A mixing matrix may mix the plurality of stems in accordance with the selected subset of rules to provide three or more output channels.

Abstract: Embodiments of systems and methods for user enrollment in speaker authentication and speaker identification systems are disclosed. In some embodiments, the enrollment process includes collecting speech samples that are examples of multiple speech types spoken by a user, computing a speech representation for each speech sample, and aggregating the example speech representations to form a robust overall representation or user voiceprint of the user's speech.

Abstract: Deep-learning classifier training systems and methods for training a classification system based on machine learning are disclosed. In some embodiments the training is configured to form classification regions of a specified shape. In some embodiments the training is configured to form classification regions in accordance with specified classification criteria. The systems and methods disclosed for training a classification system lead to improved inference performance.