Abstract: In general, techniques are described for inserting audio channels into descriptions of soundfields. A device comprising a processor may be configured to perform the techniques. The processor may be configured to obtain an audio channel separate from a higher-order ambisonic representation of a soundfield. The processor may further be configured to insert the audio channel at a spatial location within the soundfield such that the audio channel is able to be extracted from the soundfield.

Abstract: In general, techniques are described for low frequency rendering of higher-order ambisonic audio data. As an example, a device comprising a memory and a processor may perform the techniques. The memory may be configured to store higher-order ambisonic coefficients. The processor may be configured to obtain a renderer to be used when rendering the higher-order ambisonic coefficients into a speaker feed for a low frequency speaker.

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 signaling an order format for higher-order ambisonic audio data. An audio decoding device including a memory and a processor may perform the techniques. The memory may be configured to store a bitstream indicative of a coded higher-order ambisonic (HOA) audio signal. The processor may be configured to obtain, from the bitstream, a harmonic coefficient ordering format indicator indicative of a symmetric harmonic coefficient ordering format for a source set of HOA coefficients from which the coded HOA audio signal is generated. The processor may further be configured to decode the coded HOA audio signal based on the symmetric harmonic coefficient ordering format indicator.

Abstract: In general, techniques are described for coding an ambient higher order ambisonic coefficient. An audio decoding device comprising a memory and a processor may perform the techniques. The memory may store a first frame of a bitstream and a second frame of the bitstream. The processor may obtain, from the first frame, one or more bits indicative of whether the first frame is an independent frame that includes additional reference information to enable the first frame to be decoded without reference to the second frame. The processor may further obtain, in response to the one or more bits indicating that the first frame is not an independent frame, prediction information for first channel side information data of a transport channel. The prediction information may be used to decode the first channel side information data of the transport channel with reference to second channel side information data of the transport channel.

Abstract: In general, techniques are described for indicating frame parameter reusability for decoding vectors. A device comprising a processor and a memory may perform the techniques. The processor may be configured to obtain a bitstream comprising a vector representative of an orthogonal spatial axis in a spherical harmonics domain. The bitstream may further comprise an indicator for whether to reuse, from a previous frame, at least one syntax element indicative of information used when compressing the vector. The memory may be configured to store the bitstream.

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: In general, techniques are described for compressing higher order ambisonics (HOA) audio data. A device comprising one or more processors may be configured to perform the techniques. The one or more processors may be configured to obtain a plurality of spherical harmonic coefficients from a plurality of near field compensated spherical harmonic coefficients by, at least in part, counterbalancing application of a near field compensation filter to the plurality of spherical harmonic coefficients.

Abstract: A method of analyzing an audio signal is disclosed. A digital representation of an audio signal is received and a first output function is generated based on a response of a physiological model to the digital representation. At least one property of the first output function may be determined. One or more values are determined for use in analyzing the audio signal, based on the determined property of the first output function.

Abstract: In general, techniques are described for coding of spherical harmonic coefficients representative of a three dimensional soundfield. A device comprising a memory and one or more processors may be configured to perform the techniques. The memory may be configured to store a plurality of spherical harmonic coefficients. The one or more processors may be configured to perform an energy analysis with respect to the plurality of spherical harmonic coefficients to determine a reduced version of the plurality of spherical harmonic coefficients.

Abstract: A method for measuring speech signal quality by an electronic device is described. The method includes obtaining a modified single-channel speech signal. The method also includes estimating multiple objective distortions based on the modified single-channel speech signal. The multiple objective distortions include at least one foreground distortion and at least one background distortion. The method further includes estimating a foreground quality and a background quality based on the multiple objective distortions. The method additionally includes estimating an overall quality based on the foreground quality and the background quality.

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: A device comprising one or more processors is configured to apply adaptively determined weights to a plurality of channels of the audio signal to generate a plurality of adaptively weighted channels of the audio signal. The processors are further configured to combine at least two of the plurality of adaptively weighted channels of the audio signal to generate a combined signal. The processors are further configured to apply a binaural room impulse response filter to the combined signal to generate a binaural audio signal.

Abstract: In general, techniques are described by which to perform spatial masking with respect to spherical harmonic coefficients. As one example, an audio encoding device comprising a processor may perform various aspects of the techniques. The processor may be configured to perform spatial analysis based on the spherical harmonic coefficients describing a three-dimensional sound field to identify a spatial masking threshold. The processor may further be configured to render the multi-channel audio data from the plurality of spherical harmonic coefficients, and compress the multi-channel audio data based on the identified spatial masking threshold to generate a bitstream.

Abstract: In general, techniques are described for obtaining decomposed versions of spherical harmonic coefficients. A device comprising one or more processors may be configured to perform the techniques, whereby the processors may be configured to obtain, from a bitstream, at least one of one or more vectors decomposed from spherical harmonic coefficients that were recombined with background spherical harmonic coefficients, wherein the spherical harmonic coefficients describe a sound field, and wherein the background spherical harmonic coefficients described one or more background components of the same sound field.

Abstract: In general, techniques are described for performing a positional analysis to code audio data. Typically, this audio data comprises a hierarchical representation of a soundfield and may include, as one example, spherical harmonic coefficients (which may also be referred to as higher-order ambisonic coefficients). An audio compression device that includes one or more processors may perform the techniques. The processors may be configured to allocate bits to one or more portions of the audio data, at least in part by performing positional analysis on the audio data.

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 performing order reduction with respect to a plurality of spherical harmonic coefficients. In accordance with the techniques, a device comprising one or more processors may be configured to perform, based on a target bitrate, order reduction with respect to a plurality of spherical harmonic coefficients or decompositions thereof to generate reduced spherical harmonic coefficients or the reduced decompositions thereof, wherein the plurality of spherical harmonic coefficients represent a sound field.

Abstract: A device comprising one or more processors is configured to obtain transformation information, the transformation information describing how a sound field was transformed to reduce a number of a plurality of hierarchical elements to a reduced plurality of hierarchical elements; and perform binaural audio rendering with respect to the reduced plurality of hierarchical elements based on the transformation information.

Abstract: In general, techniques are described for identifying distinct audio objects from spherical harmonic coefficients (which may also be denotes as higher order ambisonic coefficients). A device comprising one or more processors may perform the techniques so as to identify the distinct audio objects from the spherical harmonic coefficients (SHC) associated with the audio objects based on a directionality determined for one or more of the audio objects.