The present disclosure relates to reverberation generation for headphone virtualization. A method of generating one or more components of a binaural room impulse response (BRIR) for headphone virtualization is described. In the method, directionally-controlled reflections are generated, wherein directionally-controlled reflections impart a desired perceptual cue to an audio input signal corresponding to a sound source location. Then at least the generated reflections are combined to obtain the one or more components of the BRIR. Corresponding system and computer program products are described as well.

An audio encoder comprises a multi-channel receiver which receives an M-channel audio signal where M>2. A down-mix processor down-mixes the M-channel audio signal to a first stereo signal and associated parametric data and a spatial processor modifies the first stereo signal to generate a second stereo signal in response to the associated parametric data and spatial parameter data for a binaural perceptual transfer function, such as a Head Related Transfer Function (HRTF). The second stereo signal is a binaural signal and may specifically be a (3D) virtual spatial signal. An output data stream comprising the encoded data and the associated parametric data is generated by an encode processor and an output processor. The HRTF processing may allow the generation of a (3D) virtual spatial signal by conventional stereo decoders. A multi-channel decoder may reverse the process of the spatial processor to generate an improved quality multi-channel signal.

According to the present disclosure, a sound output device includes: a sound acquisition part configured to acquire sound to be output to the other end of a sound guide part, one end of which is arranged near an entrance of an ear canal of a listener, the sound guide part having a hollow structure; and a head-related transfer function adjustment part configured to adjust a head-related transfer function of sound captured by the sound guide part. Since the head-related transfer function adjustment part adjusts the head-related transfer function of sound captured by the sound guide part, it is possible to listen to both ambient sound and sound provided from a sound output device such that the listener does not feel strangeness even in the state in which the listener is wearing the sound output device.

A method for processing an audio signal in accordance with a room impulse response is described. The audio signal is separately processed with an early part and a late reverberation of the room impulse response, and the processed early part of the audio signal and the reverberated signal are combined. A transition from the early part to the late reverberation in the room impulse response is reached when a correlation measure reaches a threshold, the threshold being set dependent on the correlation measure for a selected one of the early reflections in the early part of the room impulse response.

In some embodiments, virtualization methods for generating a binaural signal in response to channels of a multi-channel audio signal, which apply a binaural room impulse response (BRIR) to each channel including by using at least one feedback delay network (FDN) to apply a common late reverberation to a downmix of the channels. In some embodiments, input signal channels are processed in a first processing path to apply to each channel a direct response and early reflection portion of a single-channel BRIR for the channel, and the downmix of the channels is processed in a second processing path including at least one FDN which applies the common late reverberation. Typically, the common late reverberation emulates collective macro attributes of late reverberation portions of at least some of the single-channel BRIRs. Other aspects are headphone virtualizers configured to perform any embodiment of the method.

An audio headset may receive a plurality of audio signals corresponding to plurality of surround sound channels. The headset may determine, via its audio processing circuitry, context and/or content of the audio signals. The audio processing circuitry may process the audio signals to generate stereo signals carrying one or more virtual surround channels, wherein the processing comprises automatically controlling, based on the context and the content of the audio signals, a simulated acoustic environment of the virtual surround channels.

In device having at least one microphone and one or more speakers, environmental sound may be recorded using the microphone, classified and mixed with source media sound to produce a mixed sound depending on the classification. The mixed sound may then be played over the one or more speakers.

The present disclosure relates to reverberation generation for headphone virtualization. A method of generating one or more components of a binaural room impulse response (BRIR) for headphone virtualization is described. In the method, directionally-controlled reflections are generated, wherein directionally-controlled reflections impart a desired perceptual cue to an audio input signal corresponding to a sound source location. Then at least the generated reflections are combined to obtain the one or more components of the BRIR. Corresponding system and computer program products are described as well.

An audio encoder comprises a multi-channel receiver which receives an M-channel audio signal where M>2. A down-mix processor down-mixes the M-channel audio signal to a first stereo signal and associated parametric data and a spatial processor modifies the first stereo signal to generate a second stereo signal in response to the associated parametric data and spatial parameter data for a binaural perceptual transfer function, such as a Head Related Transfer Function (HRTF). The second stereo signal is a binaural signal and may specifically be a (3D) virtual spatial signal. An output data stream comprising the encoded data and the associated parametric data is generated by an encode processor and an output processor. The HRTF processing may allow the generation of a (3D) virtual spatial signal by conventional stereo decoders. A multi-channel decoder may reverse the process of the spatial processor to generate an improved quality multi-channel signal.

Systems and methods for providing improved localization of recorded and played back sound are provided by improved microphone arrays for recording sound and by improved systems for playback of sound. Microphone arrays include four microphones with sound transducers located and aimed to mimic capture of sound by human ears. Sound captured by two side-viewing microphones is attenuated, at the time of sound capture and/or recording, at a later processing stage, or at the time of sound playback, by low-pass filtering. The recording maintains four separate channels of sound. Playback occurs through four speakers arranged to reproduce sound in the way human ears hear sound, with appropriate attenuation for side speakers. Playback can also occur through four-channel headphones. Improved playback of two-channel stereo sound can also occur through low-pass filtering of each track and playing the filtered sound through side/rear speakers on the opposite sides.