Abstract: In general, techniques are described for closed loop quantization of HOA coefficients that provide a three-dimensional representation of the sound field. An audio encoding device may perform closed loop quantization of an audio object based at least in part on a result of performing quantization of directional information associated with the audio object. An audio decoding device may obtain an audio object that has been closed loop quantized based at least in part on a result of performing quantization of directional information associated with the audio object, and may dequantize the audio object.

Abstract: In one example, a method includes obtaining a representation of a multi-channel audio signal for a source loudspeaker configuration; obtaining a representation of a plurality of spatial positioning vectors (SPVs), in a Higher-Order Ambisonics (HOA) domain, that are based on a source rendering matrix, which is based on the loudspeaker configuration; and generating a HOA soundfield based on the multi-channel audio signal and the plurality of spatial positioning vectors.

Abstract: In general, techniques are described for coding higher-order ambisonic coefficients during multiple transitions. A device comprising a processor and a memory coupled to the processor may be configured to perform the techniques. The processor may be configured to obtain a multi-transition indication of whether an ambient HOA coefficient is in transition during a same frame of the bitstream as a foreground audio signal is in transition. The processor may also be configured to obtain a vector that describes a spatial characteristic of a corresponding foreground audio signal based on the multi-transition indication, both the vector and the corresponding HOA audio signal decomposed from the HOA audio data. The memory may be configured to store the vector.

Abstract: A device obtains an object-based representation of an audio signal of an audio object. The audio signal corresponds to a time interval. Additionally, the device obtains a representation of a spatial vector for the audio object, wherein the spatial vector is defined in a Higher-Order Ambisonics (HOA) domain and is based on a first plurality of loudspeaker locations. The device generates, based on the audio signal of the audio object and the spatial vector, a plurality of audio signals. Each respective audio signal of the plurality of audio signals corresponds to a respective loudspeaker in a plurality of local loudspeakers at the second plurality of loudspeaker locations different from the first plurality of loudspeaker locations.

Abstract: In general, techniques are described for specifying spherical harmonic coefficients in a bitstream. A device comprising one or more processors may perform the techniques. The processors may be configured to identify, from the bitstream, a plurality of hierarchical elements describing a sound field that are included in the bitstream. The processors may further be configured to parse the bitstream to determine the identified plurality of hierarchical elements.

Abstract: This disclosure describes techniques for coding of higher-order ambisonics audio data comprising at least one higher-order ambisonic (HOA) coefficient corresponding to a spherical harmonic basis function having an order greater than one. This disclosure describes techniques for adjusting HOA soundfields to potentially improve spatial alignment of the acoustic elements to the visual component in a mixed audio/video reproduction scenario. In one example, a device for rendering an HOA audio signal includes one or more processors configured to render the HOA audio signal over one or more speakers based on one or more field of view (FOV) parameters of a reference screen and one or more FOV parameters of a viewing window.

Abstract: Methods and apparatuses are disclosed for streaming audio between a source device and a destination device. An example method may include determining an available bandwidth between the source device and the destination device. The example method may also include determining a bit rate for streaming audio from the source device to the destination device, wherein the bit rate is based on the available bandwidth. The example method may further include determining a preferred audio characteristic for streaming audio from the source device to the destination device, wherein the preferred audio characteristic is based on a user preference. The example method may also include determining encoded audio to be transmitted from the source device to the destination device based on the preferred audio characteristic and the bit rate.

Abstract: In general, techniques are described for transitioning an ambient higher order ambisonic coefficient. A device comprising a memory and a processor may be configured to perform the techniques. The processor may obtain, from a frame of a bitstream of encoded audio data, a bit indicative of a reduced vector. The reduced vector may represent, at least in part, a spatial component of a sound field. The processor may also obtain, from the frame, a bit indicative of a transition of an ambient higher-order ambisonic coefficient. The ambient higher-order ambisonic coefficient may represent, at least in part, an ambient component of the sound field. The reduced vector may include a vector element associated with the ambient higher-order ambisonic coefficient in transition. The memory may be configured to store the frame of the bitstream.

Abstract: A method for reducing vibration noise by an electronic device is described. The method includes obtaining an audio signal. The audio signal includes vibration noise. The method also includes obtaining vibration data from one or more motion sensor signals. The method further includes processing the vibration data to produce microphone-response matched vibration data based on a transfer function. The method additionally includes reducing the vibration noise based on the microphone-response matched vibration data.

Abstract: In a particular aspect, a multimedia device includes one or more sensors configured to generate first sensor data and second sensor data. The first sensor data is indicative of a first position at a first time and the second sensor data is indicative of a second position at a second time. The multimedia device further includes a processor coupled to the one or more sensors. The processor is configured to generate a first version of a spatialized audio signal, determine a cumulative value based on an offset, the first position, and the second position, and generate a second version of the spatialized audio signal based on the cumulative value.

Abstract: In general, techniques are described for obtaining one or more first vectors describing distinct components of a soundfield and one or more second vectors describing background components of the soundfield, both the one or more first vectors and the one or more second vectors generated at least by performing a transformation with respect to a plurality of spherical harmonic coefficients.

Abstract: In general, techniques are described for obtaining audio rendering information in a bitstream. A device configured to render higher order ambisonic coefficients comprising a processor and a memory may perform the techniques. The processor may be configured to obtain sign symmetry information indicative of sign symmetry of a matrix used to render the higher order ambisonic coefficients to generate a plurality of speaker feeds. The memory may be configured to store the sparseness information.

Abstract: In general, techniques are described for obtaining audio rendering information in a bitstream. A device configured to render higher order ambisonic coefficients comprising a processor and a memory may perform the techniques. The processor may be configured to obtain sparseness information indicative of a sparseness of a matrix used to render the higher order ambisonic coefficients to a plurality of speaker feeds. The memory may be configured to store the sparseness information.

Abstract: In general, techniques are described for performing an interpolation with respect to decomposed versions of a sound field. A device comprising one or more processors may be configured to perform the techniques. The processors may be configured to obtain decomposed interpolated spherical harmonic coefficients for a time segment by, at least in part, performing an interpolation with respect to a first decomposition of a first plurality of spherical harmonic coefficients and a second decomposition of a second plurality of spherical harmonic coefficients.

Abstract: In general, techniques are described for coding of vectors decomposed from higher order ambisonic coefficients. A device comprising a processor and a memory may perform the techniques. The processor may be configured to obtain from a bitstream data indicative of a plurality of weight values that represent a vector that is included in a decomposed version of the plurality of HOA coefficients. Each of the weight values may correspond to a respective one of a plurality of weights in a weighted sum of code vectors that represents the vector and that includes a set of code vectors. The processor may further be configured to reconstruct the vector based on the weight values and the code vectors. The memory may be configured to store the reconstructed vector.

Abstract: In general, techniques are directed to intermediate compression of higher order ambisonic audio data. For example, a device comprising a processor and a memory may be configured to perform the techniques. The memory may be configured to store an intermediately formatted audio data generated as a result of an intermediate compression of higher order ambisonic audio data. The one or more processors may be configured to process the intermediately formatted audio data.

Abstract: In general, techniques are described for compression and decoding of audio data are generally disclosed. An example device for compressing audio data includes one or more processors configured to apply a decorrelation transform to ambient ambisonic coefficients to obtain a decorrelated representation of the ambient ambisonic coefficients, the ambient HOA coefficients having been extracted from a plurality of higher order ambisonic coefficients and representative of a background component of a soundfield described by the plurality of higher order ambisonic coefficients, wherein at least one of the plurality of higher order ambisonic coefficients is associated with a spherical basis function having an order greater than one.

Abstract: A method for feature extraction by an electronic device is described. The method includes processing speech using a physiological cochlear model. The method also includes analyzing sections of an output of the physiological cochlear model. The method further includes extracting a place-based analysis vector and a time-based analysis vector for each section. The method additionally includes determining one or more features from each analysis vector.

Abstract: Systems, methods, and apparatus for backward-compatible coding of a set of basis function coefficients that describe a sound field are presented.

Abstract: In general, techniques are described for obtaining spherical harmonic coefficients (SHC). A device comprising a processor and a memory may be configured to perform the techniques. The processor may obtain a set of coefficients of a vector representative a distinct component of a sound field, the vector having been decomposed from SHC representative of the sound field. The processor may obtain a configuration mode by which to extract the coefficients, where the configuration mode indicates that the coefficients include coefficients corresponding to an order greater than an order of a basis function to which one or more of the spherical harmonic coefficients correspond and exclude at least one of the coefficients corresponding to a greater order. The processor may extract the coefficients of the vector based on the obtained configuration mode. The memory may be configured to store the non-zero set of the coefficients of the vector.