Abstract: Techniques for estimating a direction of arrival of sound in an environment are discussed. First and second audio data are received from a first pair of audio sensors associated with a vehicle. A first region of ambiguity associated with the first pair of audio sensors is determined based on the first and second audio data. Third and fourth audio data are received from a second pair of audio sensors. A second region of ambiguity associated with the second pair of audio sensors is determined based on the third and fourth audio data. The regions of ambiguity can be further based on confidence levels associated with sensor or audio data. An area of intersection of the first region of ambiguity and the second region of ambiguity can be determined. A direction of arrival of an audio event can be determined based on the area of intersection.

Abstract: A device for signal processing includes a memory and a processor. The memory is configured to store a parameter associated with a bandwidth-extended audio stream. The processor is configured to select a plurality of non-linear processing functions based at least in part on a value of the parameter. The processor is also configured to generate a high-band excitation signal based on the plurality of non-linear processing functions.

Abstract: Techniques for determining a direction of arrival of an emergency are discussed. A plurality of audio sensors of a vehicle can receive audio data associated with the vehicle. An audio sensor pair can be selected from the plurality of audio sensors to generate audio data representing sound in an environment of the vehicle. An angular spectrum associated with the audio sensor pair can be determined based on the audio data. A feature associated with the audio data can be determined based on the angular spectrum and/or the audio data itself. A direction of arrival (DoA) value associated with the sound may be determined based on the feature using a machine learned model. An emergency sound (e.g., a siren) can be detected in the audio data and a direction associated with the emergency relative to the vehicle can be determined based on the feature and the DoA value.

Abstract: An apparatus includes a receiver and a decoder. The receiver is configured to receive a bitstream that includes a first frame and a second frame. The first frame includes a first portion of a mid channel and a first quantized stereo parameter. The second frame includes a second portion of the mid channel and a second quantized stereo parameter. The decoder is configured to generate a first portion of a channel based on the first portion of the mid channel and the first quantized stereo parameter. The decoder is configured to, in response to the second frame being unavailable for decoding operations, estimate the second quantized stereo parameter based on stereo parameters of one or more preceding frames and generate a second portion of the channel based on the estimated second quantized stereo parameter. The second portion of the channel corresponds to a decoded version of the second frame.

Abstract: An apparatus includes a receiver and a decoder. The receiver is configured to receive a bitstream that includes a first frame and a second frame. The first frame includes a first portion of a mid channel and a first quantized stereo parameter. The second frame includes a second portion of the mid channel and a second quantized stereo parameter. The decoder is configured to generate a first portion of a channel based on the first portion of the mid channel and the first quantized stereo parameter. The decoder is configured to, in response to the second frame being unavailable for decoding operations, estimate the second quantized stereo parameter based on stereo parameters of one or more preceding frames and generate a second portion of the channel based on the estimated second quantized stereo parameter. The second portion of the channel corresponds to a decoded version of the second frame.

Abstract: An apparatus includes a receiver and an up-mixer. The receiver is configured to receive a bitstream that includes an encoded mid signal and encoded stereo parameter information. The encoded stereo parameter information represents a first value of a stereo parameter and a second value of the stereo parameter. The first value is associated with a first frequency range. The second value is associated with a second frequency range that is distinct from the first frequency range. The up-mixer is configured to perform an up-mix operation on a frequency-domain decoded mid signal generated from the encoded mid signal. A particular value based on the first value and the second value is applied to the frequency-domain decoded mid signal during the up-mix operation.

Abstract: Techniques for determining information associated with sounds detected in an environment based on audio data and map data or perception data are discussed herein. A vehicle can use map data and/or perception data to distinguish between multiple audio signals or sounds. A direct source of sound can be distinguished from a reflected source of sound by determining a direction of arrival of sounds and which objects the directions of arrival are associated with in the environment. A reflected sound can be received without receiving a direct sound. Based on the reflected sound and map data or perception data, characteristics of sound in an occluded region of the environment may be determined and used to control the vehicle.

Abstract: Techniques for determining information associated with sounds detected in an environment based on audio data and map data or perception data are discussed herein. A vehicle can use map data and/or perception data to distinguish between multiple audio signals or sounds. A direct source of sound can be distinguished from a reflected source of sound by determining a direction of arrival of sounds and which objects the directions of arrival are associated with in the environment. A reflected sound can be received without receiving a direct sound. Based on the reflected sound and map data or perception data, characteristics of sound in an occluded region of the environment may be determined and used to control the vehicle.

Abstract: A device for processing audio signals includes an interchannel phase difference (IPD) mode selector and an IPD estimator. The IPD mode selector is configured to select an IPD mode from among at least a first IPD mode and a second IPD mode based on at least an interchannel temporal mismatch value indicative of a temporal misalignment between a first audio signal and a second audio signal. The IPD estimator is configured to determine IPD values based on the first audio signal and the second audio signal, the IPD values represented using a first number of bits responsive to selection of the first IPD mode or represented using a second number of bits responsive to selection of the second IPD mode.

Abstract: An apparatus includes a receiver and an up-mixer. The receiver is configured to receive a bitstream that includes an encoded mid signal and encoded stereo parameter information. The encoded stereo parameter information represents a first value of a stereo parameter and a second value of the stereo parameter. The first value is associated with a first frequency range. The second value is associated with a second frequency range that is distinct from the first frequency range. The up-mixer is configured to perform an up-mix operation on a frequency-domain decoded mid signal generated from the encoded mid signal. A particular value based on the first value and the second value is applied to the frequency-domain decoded mid signal during the up-mix operation.

Abstract: A device includes an encoder configured to determine, during a first period, that a first audio signal is a leading signal and that a second audio signal is a lagging signal. The encoder is also configured to generate a first frame of at least one encoded signal based on a first modified version of the second audio signal that is generated by adjusting the second audio signal based on a first mismatch value. The encoder is configured to determine, during a second period, that the first audio signal is the leading signal and that the second audio signal is the lagging signal. The encoder is configured to generate a second frame of the at least one encoded signal based on a second modified version of the second audio signal that is generated by adjusting the second audio signal based on the first mismatch value and a second mismatch value.

Abstract: A device includes an encoder and a transmitter. The encoder is configured to generate a first high-band portion of a first signal based on a left signal and a right signal. The encoder is also configured to generate a set of adjustment gain parameters based on a high-band non-reference signal. The high-band non-reference signal corresponds to one of a left high-band portion of the left signal or a right high-band portion of the right signal as a high-band non-reference signal. The transmitter is configured to transmit information corresponding to the first high-band portion of the first signal. The transmitter is also configured to transmit the set of adjustment gain parameters corresponding to the high-band non-reference signal.

Abstract: A device includes an encoder configured to generate a first high-band portion of a first signal based on a left signal and a right signal. The encoder is also configured to generate a set of adjustment gain parameters based on a high-band non-reference signal and a synthesized signal. The high-band non-reference signal corresponds to one of a left high-band portion of the left signal or a right high-band portion of the right signal.

Abstract: Techniques for determining a direction of arrival of an emergency are discussed. A plurality of audio sensors of a vehicle can receive audio data associated with the vehicle. An audio sensor pair can be selected from the plurality of audio sensors to generate audio data representing sound in an environment of the vehicle. An angular spectrum associated with the audio sensor pair can be determined based on the audio data. A feature associated with the audio data can be determined based on the angular spectrum and/or the audio data itself. A direction of arrival (DoA) value associated with the sound may be determined based on the feature using a machine learned model. An emergency sound (e.g., a siren) can be detected in the audio data and a direction associated with the emergency relative to the vehicle can be determined based on the feature and the DoA value.

Abstract: A method includes generating a synthesized non-reference high-band channel based on a non-reference high-band excitation corresponding to a non-reference target channel. The method further includes estimating one or more spectral mapping parameters based on the synthesized non-reference high-band channel and a high-band portion of the non-reference target channel. The method also includes applying the one or more spectral mapping parameters to the synthesized non-reference high-band channel to generate a spectrally shaped synthesized non-reference high-band channel. The method further includes generating an encoded bitstream based on the one or more spectral mapping parameters and the spectrally shaped synthesized non-reference high-band channel.

Abstract: An apparatus includes a decoder configured to receive, from an encoder, a frame associated with an audio bitstream and with a first sampling rate. The decoder is configured to perform a frequency-domain upmix on data associated with the frame to generate left and right frequency-domain signals and is further configured to generate, based on the left and right frequency-domain signals, left and right time-domain signals that each have a second sampling rate. The second sampling rate is determined by the decoder, based on one or both of the first sampling rate and an output sampling rate, and is adjustable by the decoder to enable different frames to be decoded at different second sampling rates. The decoder is further configured to generate, based on the left and right time-domain signals, left and right resampled signals that each have the output sampling rate.

Abstract: A device includes a receiver configured to receive an encoded bitstream from a second device. The encoded bitstream includes a temporal mismatch value. The device also includes a decoder configured to decode the encoded bitstream to generate a first signal and a second signal. Based on the temporal mismatch value, the decoder is configured to map one of the first signal or the second signal as a decoded target channel. The decoder is also configured to perform a shift operation on the decoded target channel based on the temporal mismatch value to generate an adjusted decoded target channel. The device also includes an output device configured to output a first output signal and a second output signal. The second output signal is based on the adjusted decoded target channel.

Abstract: A method of coding for multi-channel audio signals includes estimating comparison values at an encoder indicative of an amount of temporal mismatch between a reference channel and a corresponding target channel. The method includes smoothing the comparison values to generate short-term and first long-term smoothed comparison values. The method includes calculating a cross-correlation value between the comparison values and the short-term smoothed comparison values. The method also includes adjusting the first long-term smoothed comparison values in response to comparing the cross-correlation value with a threshold. The method further includes estimating a tentative shift value and non-causally shifting the target channel by a non-causal shift value to generate an adjusted target channel. The non-causal shift value is based on the tentative shift value. The method further includes generating, based on reference channel and the adjusted target channel, at least one of a mid-band channel or a side-band channel.

Abstract: A method includes processing a time-domain decoded high-band mid signal to generate a time-domain high-band residual prediction signal. The method also includes generating a high-band left channel and a high-band right channel based on the time-domain decoded high-band mid signal and the time-domain high-band residual prediction signal.

Abstract: A method includes receiving, at an audio encoder, multiple streams of audio data. The method includes assigning a priority to each stream of the multiple streams and determining, based on the priority of each stream of the multiple streams, a permutation sequence for encoding of the multiple streams. The method also includes encoding at least a portion of each stream of the multiple streams according to the permutation sequence.