Some implementations involve receiving location information for each of a plurality of audio devices in an audio environment, generating, based at least in part on the location information, rendering information for a plurality of audio devices in an audio environment and determining, based at least on part on the rendering information, a plurality of echo reference metrics. Each echo reference metric may correspond to audio data reproduced by one or more audio devices of the plurality of audio devices. The rendering information may include a matrix of loudspeaker activations. Some examples involve making, based at least in part on the echo reference metrics, an importance estimation for each of a plurality of echo references, selecting, based at least in part on the importance estimation, one or more echo references and providing them to at least one echo management system for canceling or suppressing echoes.

An audio device may be configured to produce output audio and to capture input audio for speech recognition. In some cases, a second device may also be used to capture input audio to improve isolation of input audio with respect to the output audio. In addition, acoustic echo cancellation (AEC) may be used to remove components of output audio from input signals of the first and second devices. AEC may be implemented by an adaptive filter based on dynamically optimized filter coefficients. The filter coefficients may be analyzed to detect situations in which the first and second devices are too close to each other, and the user may then be prompted to increase the distance between the two devices.

An audio processing system includes at least one first microphone, at least one adaptive filter, and a processor. The at least one first microphone acquires a first audio signal and outputs a first signal based on the first audio signal. The first audio signal includes at least one of a first audio component generated at a first position and a second audio component generated at a second position different from the first position. The first signal is input to the at least one adaptive filter. The at least one adaptive filter outputs a passing signal based on the first signal. The processor, when executing a program stored in a memory, performs: making a determination of which of the first audio component and the second audio component the first audio signal includes more; and controlling a filter coefficient of the adaptive filter based on a result of the determination.

A method for playback of an audio signal at an individual seat-based sound (ISS) system in a coherent listening environment having a plurality of ISS systems and a plurality of listening modes. Each ISS system has a single transducer. A listening mode and a set of playback preferences are selected. A crosstalk cancellation algorithm for the ISS system of interest is generated using impulse response measurements of the audio signal, taken only in an acoustical domain, of a transfer function between the audio signal directly after the single transducer in the ISS system of interest and the audio signal at the head of the listener in the ISS system of interest. The crosstalk cancellation algorithm for the selected listening mode is applied to the audio signal, and the audio signal is played back at the single transducer of the ISS system of interest.

An echo cancellation system performs audio beamforming to separate audio input into multiple directions (e.g., target signals) and generates multiple audio outputs using two acoustic echo cancellation (AEC) circuits. A first AEC removes a playback reference signal (generated from a signal sent a loudspeaker) to isolate speech included in the target signals. A second AEC removes an adaptive reference signal (generated from microphone inputs corresponding to audio received from the loudspeaker) to isolate speech included in the target signals. A beam selector receives the multiple audio outputs and selects the first AEC or the second AEC based on a linearity of the system. When linear (e.g., no distortion or variable delay between microphone input and playback signal), the beam selector selects an output from the first AEC based on signal to noise (SNR) ratios. When nonlinear, the beam selector selects an output from the second AEC.

Examples of the disclosure relate to acoustic echo cancellation using adaptive filtering modules. An apparatus for acoustic echo cancellation is configured to process a first input signal using a first acoustic echo cancellation module to obtain a first prediction signal and to process a second input signal using a second acoustic echo cancellation module to obtain a second prediction signal. The first input signal is based on a loudspeaker signal and the second input signal is a delayed first input signal. The prediction signals are processed to obtain a predicted echo signal. The predicted echo signal is applied to a received microphone signal to reduce echo from loudspeaker playback in the received microphone signal. The acoustic echo cancellation modules can be adapted using an adaptive filtering module.

A noise control system may be configured to process one or more first noise inputs from one or more first acoustic sensors, the one or more first noise inputs representing external noise sensed at one or more respective noise sensing locations on an outer surface of a sheltering structure; to process one or more second noise inputs from one or more second acoustic sensors, the one or more second noise inputs representing residual noise at one or more respective residual noise sensing locations on an inner surface of the sheltering structure; to determine a noise control pattern based at least on the one or more first noise inputs and the one or more second noise inputs; and to generate one or more control signals to control acoustic signals generated by one or more acoustic transducers based on the noise control pattern.

An interference sound suppressing device includes: an input signal acquiring part that acquires an input signal obtained from a microphone; a reference signal acquiring part that acquires a reference signal; a data inserting part that increases an amount of data of the input signal to be larger than an amount of data of the reference signal by inserting a plurality of zeros into the input signal; an interference sound suppressing part that suppresses an interference sound component included in the input signal by using the input signal having the amount of data increased and the reference signal; a data deleting part that restores the amount of data of the input signal to an original amount by deleting the plurality of zeros inserted from the input signal in which the interference sound component is suppressed; and an output part that outputs the input signal having the amount of data restored.

Example techniques involve noise-robust acoustic echo cancellation. An example implementation may involve causing one or more speakers of the playback device to play back audio content and while the audio content is playing back, capturing, via the one or more microphones, audio within an acoustic environment that includes the audio playback. The example implementation may involve determining measured and reference signals in the STFT domain. During each n.sup.th iteration of an acoustic echo canceller (AEC): the implementation may involve determining a frame of an output signal by generating a frame of a model signal by passing a frame of the reference signal through an instance of an adaptive filter and then redacting the n.sup.th frame of the model signal from an n.sup.th frame of the measured signal. The implementation may further involve determining an instance of the adaptive filter for a next iteration of the AEC.

Boomless-microphones are described for a wireless helmet communicator with siren signal detection and classification capabilities. An acoustic component receives an audio signal and comprises a left acoustic sensor and a right acoustic sensor. The left acoustic sensor is mountable or attachable to the surface of a left wall of a helmet and the right acoustic sensor is mountable or attachable to the surface of a right wall. A speaker component can generate an echoless audio signal via signal inversion of the audio signal, outputs to a left speaker mountable or attachable to a left ear area of the helmet and a right speaker mountable or attachable to a right ear area of the helmet. A signal enhancement component can increase an intensity of the first audio signal associated with an emergency siren based on a determined proximity of an emitting emergency vehicle or emergency object to the device.