There is disclosed inter alia an apparatus for spatial audio signal encoding which determines at least one spatial audio parameter comprising a direction parameter with an elevation component and an azimuth component. The elevation component and azimuth component of the direction parameter are then converted to an index value.

A method is provided for encoding multiple microphone signals into a composite source-separable audio (SSA) signal, conducive for transmission over a voice network. The embodiments enable the processing of source separation of the target voice signal from its ambient sound to be performed at any point in the voice communication network, including the internet cloud. A multiplicity of processing is possible over the SSA signal, based on the intended voice application. The level of processing is adapted with the availability of the processing power at the chosen processing node in the network in one embodiment. An apparatus for separating out the target source voice from its ambient sound is also provided. The apparatus includes a directed source separation (DSS) unit, which processes the two virtual microphone signals in the SSA representation, to generate a new SSA signal including the enhanced target voice and the enhanced ambient noise.

Systems and methods for adjusting bass levels of a multi-channel audio signal include, among other features, (i) receiving the multi-channel signal via a playback device; (ii) separating, from the multi-channel signal, low-frequency signals comprising frequencies less than a threshold frequency; (iii) determining electrical energies of the low-frequency signals; (iv) determining a first energy by summing the electrical energies of the low-frequency signals; (v) consolidating the low-frequency signals into a consolidated low-frequency signal; (vi) determining a second energy by determining an electrical energy of the consolidated low-frequency signal; (vii) generating a gain-adjusted low-frequency signal by adjusting a gain of the consolidated low-frequency signal based on both (a) the first energy and (b) the second energy; (viii) generating a gain-adjusted multi-channel signal by mixing the gain-adjusted low-frequency signal back into the multi-channel signal; and (ix) using the gain-adjusted multi-channel signal to play back gain-adjusted multi-channel audio content via the playback device.

An circuit includes: a plurality of analog-to-digital converters (ADCs) and a control chip. The control chip is utilized for instructing a target ADC to output audio data of a target channel during a target period, and utilized for instructing remaining ADCs not to output audio data in the target period. Then, the control chip defines data timing of the target channel and other channels based on the data receiving time point of the audio data of the target channel. The plurality of ADCs would process analog audio signals of a plurality of channels and output audio data of the plurality of channels according to an assigned order configured by the control chip to form a serial data signal. The control chip separates the audio data of different channels from the serial data signal according to the data timing of the plurality of channels.

A system for producing an encoded digital audio recording has an audio encoder that encodes a digital audio recording having a number of audio channels or audio objects. An equalization (EQ) value generator produces a sequence of EQ values which define EQ filtering that is to be applied when decoding the encoded digital audio recording, wherein the EQ filtering is to be applied to a group of one or more of the audio channels or audio objects of the recording independent of any downmix. A bitstream multiplexer combines the encoded digital audio recording with the sequence of EQ values, the latter as metadata associated with the encoded digital audio recording. Other embodiments are also described including a system for decoding the encoded audio recording.

An apparatus for generating one or more audio output channels is provided. The apparatus includes a parameter processor for calculating output channel mixing information and a downmix processor for generating the one or more audio output channels. The downmix processor is configured to receive an audio transport signal including one or more audio transport channels, wherein two or more audio object signals are mixed within the audio transport signal, and wherein the number of the one or more audio transport channels is smaller than the number of the two or more audio object signals. The audio transport signal depends on a first mixing rule and on a second mixing rule. The first mixing rule indicates how to mix the two or more audio object signals to obtain a plurality of premixed channels. Moreover, the second mixing rule indicates how to mix the plurality of premixed channels.

A system and method can determine a time-varying position of a sound in a multi-channel audio signal. At least one processor can: receive a multi-channel audio signal representing a sound, each channel of the multi-channel audio signal providing audio associated with a corresponding channel position around a perimeter of a soundstage; determine a time-varying volume level for each channel of the multi-channel audio signal; determine, from the time-varying volume levels and the channel positions, a time-varying position in the soundstage of the sound; and generate a location data signal representing the time-varying position of the sound. The channel positions can be time-invariant. The position magnitude can be scaled to provide a unit magnitude as a sound pans from a channel to an adjacent channel. The position azimuth angle can be scaled to account for center location bias.

Imaging apparatus (100) includes selectors (115, 120) that select sound signals having a set number of channels, and a control unit. When a number of channels is set to two at time of recording sound signals, the control unit, according to a first format, records sound data generated based on selected sound signals for two channels, on one sound track included in a video file. When the number of channels is set to four, the control unit, does not record two pieces of sound data respectively on two sound tracks included in one video file in accordance with the first format.

Described herein is a method for creating an object-based audio signal from an audio input, the audio input including one or more audio channels that are recorded to collectively define an audio scene. The one or more audio channels are captured from a respective one or more spatially separated microphones disposed in a stable spatial configuration. The method includes the steps of: a) receiving the audio input; b) performing spatial analysis on the one or more audio channels to identify one or more audio objects within the audio scene; c) determining contextual information relating to the one or more audio objects; d) defining respective audio streams including audio data relating to at least one of the identified one or more audio objects; and e) outputting an object-based audio signal including the audio streams and the contextual information.

A system for producing an encoded digital audio recording has an audio encoder that encodes a digital audio recording having a number of audio channels or audio objects. An equalization (EQ) value generator produces a sequence of EQ values which define EQ filtering that is to be applied when decoding the encoded digital audio recording, wherein the EQ filtering is to be applied to a group of one or more of the audio channels or audio objects of the recording independent of any downmix. A bitstream multiplexer combines the encoded digital audio recording with the sequence of EQ values, the latter as metadata associated with the encoded digital audio recording. Other embodiments are also described including a system for decoding the encoded audio recording.