Patent Description:
However, the time that is required to retrieve the mobile device may still be too lengthy to capture some events or moments that are fleeting. Users may also feel as though they have to remove themselves from being present and living the event or moment in order to retrieve their mobile device. Further, when played back, the audio portion of the content that was recorded using the mobile device may not adequately recreate the sound as perceived by the user.

<CIT> describes a hearing aid/spectacles combination that includes a spectacle frame and a first reproduction unit. The spectacle frame has a microphone array in a first spectacle arm. The microphone array is able to pick up a sound signal and is able to transmit a processed signal, produced on the basis of the sound signal, to the first reproduction unit. The hearing aid/spectacles combination includes a sound registration module that includes the microphone array; a beam forming module for forming a direction-dependent processed signal; a reproduction adaptation module for controlling a reproduction characteristic of the processed sound signal produced by the first reproduction unit; a reproduction module that comprises the first reproduction unit; and a reproduction control module for controlling a reproduction characteristic of the processed sound signal produced by the first reproduction unit; the beam forming module and the reproduction adaptation module can be based on digital techniques.

<CIT> concerns hearing aid glasses with a left temple and a right temple connected to a front portion supporting a pair of lenses, at least one temple with one single microphone and a processor connected to the single microphone. The single microphone is an omnidirectional microphone and located in the temple such that, when the hearing glasses are worn by a human's head where the at least one temple is at a predetermined side of the head, the single microphone can receive sound substantially unblocked by the head from sound sources both at a left and right frontal side of the head, as well as from one back side of the head corresponding to the predetermined side of the head.

<CIT> concerns a directional indicative hearing apparatus comprising: a pair of hearing aids; an eyeglass frame having a bridge; and a pair of temples for positioning the eyeglasses and hearing apparatus on an individual's head. The microphones are disposed in or on the temples together with a pair of vibrators and batteries for indicating whether the sound emanates from the right, the left or behind an individual. In addition, the apparatus includes a pair of LEDs for indicating if the sound is emanating from the right, the left or in front of the individual.

<CIT> relates to the acquisition, processing and rendering of acoustic signals. One or more direction specific audio signals may be generated using a microphone array comprising two or more microphones and an audio stream generator. The audio stream generator may receive a direction parameter from an optical tracking system. Also described is an audio rendering system adapted to normalize and/or balance acoustic signals acquired from a soundscape.

<CIT> describes a wearable device for binaural audio. The wearable device includes a feedback mechanism, a microphone, an always-on binaural recorder (AOBR), and a processor. The AOBR is to capture ambient noise via the microphone and interpret the ambient noise. An alert is issued by the processor to the feedback mechanism based on a notification detected via the microphone in the ambient noise.

The invention is a head-wearable apparatus, a pair of eyeglasses and a method as defined in the appended claims.

To improve on audio recording that is captured by current electronic mobile devices, some embodiments of the disclosure are directed to a head-wearable apparatus <NUM> that can capture audio content, which when played back, is an imitation of the sound as perceived by the user of the head-wearable apparatus <NUM>. Specifically, the head-wearable apparatus <NUM> can record audio using microphones that are arranged to create <NUM>-dimensional (3D) sound sensation for the listener as if present when the audio was recorded. This is called binaural audio. The playback of the captured audio content will have the effect of binaural audio that has the stereo separation and the spectral content that would mimic a human ear and head response. The design of the head-wearable apparatus <NUM> uses, among other things, the diffraction pattern of the human head, the placement of the microphones on both sides of the head, and beamforming techniques.

<FIG> illustrates a perspective view of a head-wearable apparatus <NUM> to generate binaural audio according to one example embodiment. <FIG> illustrates a bottom view of the head-wearable apparatus <NUM> from <FIG>, according to one example embodiment. In <FIG>, the head-wearable apparatus <NUM> is a pair of eyeglasses. In some embodiments, the head-wearable apparatus <NUM> can be sunglasses or goggles. Some embodiments can include one or more wearable devices, such as a pendant with an integrated camera that is integrated with, in communication with, or coupled to, the head-wearable apparatus <NUM> or a client device. Any desired wearable device may be used in conjunction with the embodiments of the present disclosure, such as a watch, a headset, a wristband, earbuds, clothing (such as a hat or jacket with integrated electronics), a clip-on electronic device, or any other wearable devices. It is understood that, while not shown, one or more portions of the system included in the head-wearable apparatus can be included in a client device (e.g., machine <NUM> in <FIG>) that can be used in conjunction with the head-wearable apparatus <NUM>. For example, one or more elements as shown in <FIG> can be included in the head-wearable apparatus <NUM> and/or the client device.

As used herein, the term "client device" may refer to any machine that interfaces to a communications network to obtain resources from one or more server systems or other client devices. A client device may be, but is not limited to, a mobile phone, desktop computer, laptop, portable digital assistants (PDAs), smart phones, tablets, ultra books, netbooks, laptops, multi-processor systems, microprocessor-based or programmable consumer electronics, game consoles, set-top boxes, or any other communication device that a user may use to access a network.

In <FIG>, the head-wearable apparatus <NUM> is a pair of eyeglasses that includes a frame <NUM> that includes eye wires (or rims) that are coupled to two stems (or temples), respectively, via hinges and/or end pieces. The eye wires of the frame <NUM> carry or hold a pair of lenses 104_1, 104_2. The frame <NUM> includes a first (e.g., right) side that is coupled to the first stem and a second (e.g., left) side that is coupled to the second stem. The first side is opposite the second side of the frame <NUM>.

The apparatus <NUM> further includes a camera module that includes camera lenses 102_1, 102_2 and at least one image sensor. The camera lens may be a perspective camera lens or a non-perspective camera lens. A non-perspective camera lens may be, for example, a fisheye lens, a wide-angle lens, an omnidirectional lens, etc. The image sensor captures digital video through the camera lens. The images may be also be still image frame or a video including a plurality of still image frames. The camera module can be coupled to the frame <NUM>. As shown in <FIG>, the frame <NUM> is coupled to the camera lenses <NUM><NUM>, <NUM><NUM> such that the camera lenses face forward. The camera lenses 102_1, 102_2 can be perpendicular to the lenses 104_1, 104_2. The camera module can include dual-front facing cameras that are separated by the width of the frame <NUM> or the width of the head of the user of the apparatus <NUM>.

In <FIG>, the two stems (or temples) are respectively coupled to microphone housings 101_1, 101_2. The first and second stems are coupled to opposite sides of a frame <NUM> of the head-wearable apparatus <NUM>. The first stem is coupled to the first microphone housing 101_1 and the second stem is coupled to the second microphone housing 101_2. The microphone housings 101_1, 101_2 can be coupled to the stems between the locations of the frame <NUM> and the temple tips. The microphone housings 101_1, 101_2 can be located on either side of the user's temples when the user is wearing the apparatus <NUM>.

As shown in <FIG>, the microphone housings 101_1, 101_2 encase a plurality of microphones 110_1 to <NUM> N (N><NUM>). The microphones <NUM><NUM> to <NUM> N are air interface sound pickup devices that convert sound into an electrical signal. More specifically, the microphones 110_1 to 110_N are transducers that convert acoustic pressure into electrical signals (e.g., acoustic signals). Microphones 110_1 to 110_N can be digital or analog microelectro-mechanical systems (MEMS) microphones. The acoustic signals generated by the microphones <NUM><NUM> to <NUM> N can be pulse density modulation (PDM) signals.

In <FIG>, the first microphone housing 101_1 encases microphones 110_3 and 110_4 and the second microphone housing 101_2 encases microphones 110_1 and <NUM><NUM>. In the first microphone housing 101_1, the first front microphone 110_3 and the first rear microphone 110_4 are separated by a predetermined distance d<NUM> and form a first order differential microphone array. In the second microphone housing 101_2, the second front microphone <NUM>10_1 and the second rear microphone 110_2 are also separated by a predetermined distance d<NUM> and form a first order differential microphone array. The predetermined distances d<NUM> and d<NUM> can be the same distance or different distances. The predetermined distances d<NUM> and d<NUM> can be set based on the Nyquist frequency. Content above the Nyquist frequency for a beamformer is irrecoverable, especially for speech. The Nyquist frequency is determined by the equation: <MAT>.

In this equation, c is the speed of sound and d is the separation between the microphones. Using this equation, in one embodiment, the predetermined distances d<NUM> and d<NUM> can be set as any value of d that results in a frequency above <NUM>, which is the cutoff for Wideband speech.

While, in <FIG>, the system <NUM> includes four microphones 110_1 to <NUM><NUM>, the number of microphones can vary. In some embodiment, the microphone housings 101_1, 101_2 can include at least two microphones and can form a microphone array. Each of the microphone housings 101_1, 101_2 can also include a battery.

A user naturally perceives audio with two ears separated by the head such that the user is able to distinguish the direction from which sound arrives. Accordingly, by placing the microphone housings 101_1, 101_2 on the stems of the head-wearable apparatus <NUM>, the head-wearable apparatus <NUM> can achieve capturing the sound as perceived by the user wearing the head-wearable apparatus <NUM>.

Referring to <FIG>, each of the microphone housings 101_1, 101_2 includes a front port and a rear port. The front port of the first microphone housing 101_1 is coupled to microphone 110_3 (e.g. first front microphone) and the rear port of the first microphone housing 10_1 <NUM> is coupled to the microphone <NUM><NUM> (e.g., first rear microphone). The front port of the second microphone housing 101_2 is coupled to microphone 110_1 (e.g. second front microphone) and the rear port of the second microphone housing 101_2 is coupled to the microphone 110_2 (e.g., second rear microphone). In one embodiment, the microphones 101_1 to <NUM><NUM> can be moved further towards the temple tips on the stems of the apparatus <NUM> (e.g., the back of the apparatus <NUM>) to accentuate the binaural effect captured by the microphones.

<FIG> illustrates details of portions of one microphone housing of the head-wearable apparatus from <FIG>, according to example embodiments. Specifically, <FIG> illustrates the details of the microphone 110_1 (e.g. second front microphone) and the front port associated therewith. While <FIG> illustrates the details of the microphone 110_1 coupled to the front port in the second microphone housing 101_2, it is understood that the details of the microphone 110_3 (e.g., first front microphone) coupled to the front port in the first microphone housing 101_1 are similar to the details in <FIG>.

<FIG> is a cutaway view of the front microphone <NUM><NUM> and the acoustic path <NUM>. As shown, the acoustic path <NUM> travels through the separation between the chunk <NUM> (e.g., second microphone housing 101_2) and a housing <NUM> of the second stem. The housing <NUM> of the stem can be made of metal. The front microphone 110_1 and the front port are pointing (or facing) downwards. For example, when the user is standing and wearing the apparatus <NUM>, the front port in <FIG> is open in a direction towards the user's feet on the ground. This design allows for the front acoustic port length and the acoustic mass to be at a minimum whilst ensuring that the front microphone 110_1 is protected in a pocket that can reduce the effect of noise (e.g., wind noise turbulence, etc.).

<FIG> illustrates details of another portion of the head-wearable apparatus from <FIG>, according to one example embodiment. Specifically, <FIG> illustrates the details of the microphone <NUM><NUM> (e.g. second rear microphone) and the rear port associated therewith. While <FIG> illustrates the details of the microphone 110_2 coupled to the rear port in the second microphone housing 101_2, it is understood that the details of the microphone 110_4 (e.g., first rear microphone) coupled to the rear port in the first microphone housing 101_1 are similar to the details in <FIG>.

<FIG> is a cutaway view of the rear microphone 110_2 and the acoustic path <NUM>. As shown, the acoustic path <NUM> travels through a separation between the chunk <NUM> (e.g., second microphone housing <NUM><NUM>) and a housing <NUM> of the second stem. The housing <NUM> of the stem in <FIG> can also be made of metal. The rear microphone <NUM><NUM> and the rear port are pointing (or facing) backwards. For example, when the user is wearing the apparatus <NUM>, the rear port in <FIG> is open in a direction towards the back of the user's head or the rear of the apparatus <NUM> (e.g., towards the temple end). With the porting being backwards in this embodiment, direct wind contact with the rear port is avoided when the user wears the apparatus <NUM>. This design further allows for the rear acoustic port length and the acoustic mass to be at a minimum whilst ensuring that the rear microphone 110_2 is protected in a pocket that can reduce the effect of noise (e.g., wind noise turbulence, etc.). In one embodiment, a mechanical filter can be applied to the rear microphone <NUM><NUM> to further improve noise immunity.

As shown in <FIG>, the microphones 110_1 to 110_4 can be part of a microphone assembly stackup that includes a flexible circuit board and a pressure sensitive adhesive (PSA) stackup that includes a waterproof membrane sandwiched between PSA layers. The waterproof membrane can protect the microphones 110_1 to 110_4 from water ingress and air leaks. The PSA stackup is then coupled to a microphone assembly housing. In some embodiments, the microphone assembly housing is the chunk <NUM> or the housing <NUM> of the second stem.

<FIG> is an exemplary flow diagram of a process of generating binaural audio using a head-wearable apparatus <NUM> from <FIG> according to various aspects of the disclosure. Although the flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. A process is terminated when its operations are completed. A process may correspond to a method, a procedure, etc. The steps of method may be performed in whole or in part, may be performed in conjunction with some or all of the steps in other methods, and may be performed by any number of different systems, such as the systems described in <FIG> and/or <FIG>. The process <NUM> may also be performed by a processor included in head-wearable apparatus <NUM> in <FIG> or by a processor included in a client device <NUM> of <FIG>.

The process <NUM> starts at operation <NUM> with microphones 110_1 to 110_4 generating acoustic signals. The microphones 110_1 to 110_4 can be MEMS microphones that convert acoustic pressure into electrical signals (e.g., acoustic signals). The first front microphone <NUM><NUM> and the first rear microphone <NUM><NUM> are encased in a first microphone 101_1 housing that is coupled on a first stem of the head-wearable apparatus <NUM>. The first front microphone 110_3 and the first rear microphone 110_4 form a first order differential microphone array. The second front microphone 110_1 and the second rear microphone 110_2 are encased in a second microphone housing <NUM><NUM> that is coupled on a second stem of the head-wearable apparatus <NUM>. The second front microphone <NUM>10_1 and the second rear microphone 110_2 form a first order differential microphone array. The first and second stems are coupled to opposite sides of a frame <NUM> of the head-wearable apparatus <NUM>. The acoustic signals can be pulse density modulation (PDM) signals.

At operation <NUM>, the audio codecs 501_1, <NUM><NUM> decode the acoustic signals from the microphones 110_1 to 110_4. The audio codec 501_2 decodes the acoustic signals from the first front microphone 110_and the first rear microphone 110_4 to generate a first decoded acoustic signal and the audio codec 501_1 decodes the second front microphone 110_1 and the second rear microphone 110_2 to generate a second decoded acoustic signal. The first and second decoded acoustic signals are pulse code modulation (PCM) signals. The first decoded acoustic signal is a PCM signal based on the acoustic signals from the first front microphone <NUM><NUM> and the first rear microphone 110_4. The second decoded acoustic signal is a PCM signal based on the acoustic signals from the second front microphone 110_1 and the second rear microphone 110_2.

At operation <NUM>, the TDM <NUM> processes the decoded acoustic signals from the audio codecs 501_1, 501_2. The TDM <NUM> processes the first and second decoded acoustic signals by time division multiplexing the first and second decoded acoustic signals. The TDM-processed signal includes the first decoded acoustic signal and the second decoded acoustic signal.

At operation <NUM>, the beamformer <NUM> beamforms the TDM-processed signal. As further described below, the beamformer <NUM> can be a fixed beamformer that includes a fixed beam patterns that is sub-cardioid or cardioid. The beamformer <NUM> beamforms the first decoded signal to generate a first beamformer signal and beamforms the second decoded signal to generate a second beamformer signal.

At operation <NUM>, the storage device <NUM> stores the beamformer signals as a two-channel file. The two-channel file can be a two-channel PCM file or a two-channel Advanced Audio Coding (AAC)/PCM file. The storage device <NUM> can be a flash storage device.

In one embodiment, a noise suppressor <NUM> suppresses noise from the first beamformer signal and the second beamformer signal and generates a first noise-suppressed signal and a second noise-suppressed signal. A speech enhancer <NUM> can enhance speech from the first noise-suppressed signal and the second noise-suppressed signal to generate a first clean signal and a second clean signal, respectively. In this embodiment, the storage device <NUM> stores the first and second clean signal as a two-channel PCM file.

<FIG> illustrates a block diagram of a system <NUM> to generate binaural audio included in the head-wearable apparatus <NUM> from <FIG>, according to one example embodiment. In some embodiments, one or more portions of the system <NUM> can be included in the head-wearable apparatus <NUM> or can be included in a client device (e.g., machine <NUM> in <FIG>) that can be used in conjunction with the head-wearable apparatus <NUM>.

System <NUM> includes the microphones 110_1 to 110_N, audio codecs 501_1, 501_2, a time-division multiplexer (TDM) <NUM>, and a binary audio processor <NUM>. The first front microphone 110_3 and the first rear microphone 110_4 encased in the first microphone housing 101_1 form a first-order differential microphone array. Similarly, the second front microphone 110_1 and the second rear microphone 110_2 encased in the second microphone housing 101_2 form another first-order differential microphone array. The microphones 110_1 to 110_4 can be analog or digital MEMS microphones. The acoustic signals generated by the microphones 110_1 to 110_4 can be pulse density modulation (PDM) signals.

The audio codec 501_1 decodes the acoustic signals from the first front microphone 110_3 and the first rear microphone 110_4 to generate a first decoded acoustic signal. The audio codec 501_2 decodes the acoustic signals from the second front microphone 110_1 and the second rear microphone 110_2 to generate a second decoded acoustic signal. The first and second decoded acoustic signals can be pulse code modulation (PCM) signals. In one embodiment, the audio codecs 501_1, 501_2 decode the acoustic signals that are PDM signals from a single-bit PDM format into a multibit pulse code modulation (PCM) format. The audio codecs 501_1, 501_2 can include PDM inputs with filters that convert the PDM signals to PCM format. In one embodiment, the audio codecs 501_1, 501_2 use a microcontroller with a synchronous serial interface to capture the PDM data stream from the microphones 110_1 to 110_4 and convert the PDM data stream into PCM format using the filters implemented in software.

The PCM signals can be interpreted by an interface of the binaural audio processor <NUM>. In some embodiments, binaural audio processor <NUM> is a Silicon-on-Chip (SoC). The SoC can include an interface, such as the I2S interface, to receive and interpret the PCM signals.

In one embodiment, the interface of the binaural audio processor <NUM> can only handle one packet (e.g., <NUM> channels of audio), the time-division multiplexer (TDM) <NUM> in the system <NUM> receives and process the first and second decoded acoustic signals (e.g., PCM signals) to generate a TDM-processed signal. The TDM <NUM> time-division multiplexes the first and second decoded acoustic signals to generate the TDM-processed signal. In one embodiment, the system <NUM> further oversamples the TDM-processed signal to allow for an input the four microphone signals. The system <NUM> can also include switches to create extra slots to allow for the microphone signals.

In one embodiment, the microphones 110_1 to <NUM><NUM><NUM> are digital MEMS microphones. The acoustic signals generated by digital MEMS microphones are relatively immune to noise, but signal integrity can still be a concern due to distortion created by parasitic capacitance, resistance, and inductance between the microphones 110_1 to 110_4 outputs and the SoC such as the binaural audio processor <NUM>. Impedance mismatches can also create reflections that can distort the signals in applications with longer distances between the digital microphones 110_1 to 110_4 and the SoC. In one embodiment, the microphones 110_1 to 110_4 are attached to flexible circuits designed to maximize signal integrity and also minimize the trace length between the elements. In this embodiment, the flexible circuits are encased in the microphone housings 101_1, 101_2.

<FIG> illustrates a block diagram of the binaural audio processor <NUM> included in the system <NUM> in <FIG>, according to one example embodiment. The binaural audio processor <NUM> includes a beamformer <NUM>, a noise suppressor <NUM>, a speech enhancer <NUM>, and a storage device <NUM>.

In one embodiment, the binaural audio processor <NUM> includes an interface that receives the TDM-processed signal. As discussed above, the TDM-processed signal is generated from the acoustic signals from the first front microphone 110_3, the first rear microphone 110_4, the second front microphone 110_1 and the second rear microphone 110_2. In one embodiment, the microphones 110_1 to <NUM><NUM> are digital MEMS microphones which are inherently omnidirectional.

The beamformer <NUM>, which has direction steering properties, is a differential beamformer that allows for a flat frequency response except for the Nyquist frequency. The beamformer <NUM> uses the transfer functions of a first-order differential microphone array. The transfer functions for the first-order differential microphone array is as follows for two microphones: <MAT> <MAT>.

In these equations above, theta θ is the angle and beta β is at <NUM> degrees, the equation simplifies to E = A + B cos θ, for a fixed frequency (or frequency independent) beam (e.g., beamformer signal). E in the simplified equation is the fixed frequency output of the beamformer. In one embodiment, the beamformer <NUM> is a fixed beamformer that includes a fixed beam pattern that is sub-cardioid with A and B coefficients of <NUM> and <NUM>, respectively. In one embodiment, the beamformer <NUM> is a fixed beamformer that includes a fixed beam pattern that is cardioid with A and B coefficients of <NUM> and <NUM>, respectively.

In one embodiment, the beamformer <NUM> receives the acoustic signals from the first front microphone 110_3, the first rear microphone 110_4, the second front microphone 110_1 and the second rear microphone 110_2. In one embodiment, the beamformer <NUM> receives the TDM-processed signal. The beamformer <NUM> generates a first beamformer signal based on the acoustic signals from the first front microphone 110_3 and the first rear microphone 110_4, and a second beamformer signal based on the acoustic signals from the second front microphone 110_1 and the second rear microphone 110_2. The storage device <NUM> can store the first and second beamformer signal as a two-channel file.

The noise suppressor <NUM> suppresses noise from the first beamformer signal and the second beamformer signal. The noise suppressor <NUM> is a two-channel noise suppressor and generates a first noise-suppressed signal and a second noise-suppressed signal. In one embodiment, the noise suppressor <NUM> can implement a noise suppressing algorithm.

The speech enhancer <NUM> enhances speech from the first noise-suppressed signal and the second noise-suppressed signal to generate a first clean signal and a second clean signal. In one embodiment, the speech enhancer <NUM> can implement a model-based speech enhancement. The speech enhancer <NUM> can perform a search for a plurality of speech signatures in the first and second noise-suppressed signals. When the speech enhancer <NUM> identifies portions in the first and second noise-suppressed signals that match at least one of the speech signatures, the speech enhancer <NUM> enhances or emphasizes the identified portions. In one embodiment, the speech enhancer <NUM> can implement a speech enhancement algorithm.

The storage device <NUM> stores the first and second clean signal from the speech enhancer <NUM> as a two-channel file. The two-channel file can be a two-channel PCM file (or two-channel AAC/PCM file) that represents the left and right channels. Storage device <NUM> can be a flash storage device.

<FIG> is a block diagram illustrating an exemplary software architecture <NUM>, which may be used in conjunction with various hardware architectures herein described. <FIG> is a non-limiting example of a software architecture and it will be appreciated that many other architectures may be implemented to facilitate the functionality described herein. The software architecture <NUM> may execute on hardware such as machine <NUM> of <FIG> that includes, among other things, processors <NUM>, memory <NUM>, and I/O components <NUM>. A representative hardware layer <NUM> is illustrated and can represent, for example, the machine <NUM> of <FIG>. The representative hardware layer <NUM> includes a processing unit <NUM> having associated executable instructions <NUM>. Executable instructions <NUM> represent the executable instructions of the software architecture <NUM>, including implementation of the methods, components and so forth described herein. The hardware layer <NUM> also includes memory or storage modules memory/storage <NUM>, which also have executable instructions <NUM>. The hardware layer <NUM> may also comprise other hardware <NUM>.

As used herein, the term "component" may refer to a device, physical entity or logic having boundaries defined by function or subroutine calls, branch points, application program interfaces (APIs), or other technologies that provide for the partitioning or modularization of particular processing or control functions. Components may be combined via their interfaces with other components to carry out a machine process. A component may be a packaged functional hardware unit designed for use with other components and a part of a program that usually performs a particular function of related functions.

Components may constitute either software components (e.g., code embodied on a machine-readable medium) or hardware components. A "hardware component" is a tangible unit capable of performing certain operations and may be configured or arranged in a certain physical manner. In various exemplary embodiments, one or more computer systems (e.g., a standalone computer system, a client computer system, or a server computer system) or one or more hardware components of a computer system (e.g., a processor or a group of processors) may be configured by software (e.g., an application or application portion) as a hardware component that operates to perform certain operations as described herein. A hardware component may also be implemented mechanically, electronically, or any suitable combination thereof. For example, a hardware component may include dedicated circuitry or logic that is permanently configured to perform certain operations.

A hardware component may be a special-purpose processor, such as a Field-Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC). A hardware component may also include programmable logic or circuitry that is temporarily configured by software to perform certain operations. For example, a hardware component may include software executed by a general-purpose processor or other programmable processor. Once configured by such software, hardware components become specific machines (or specific components of a machine) uniquely tailored to perform the configured functions and are no longer general-purpose processors. It will be appreciated that the decision to implement a hardware component mechanically, in dedicated and permanently configured circuitry, or in temporarily configured circuitry (e.g., configured by software) may be driven by cost and time considerations.

A processor may be, or in include, any circuit or virtual circuit (a physical circuit emulated by logic executing on an actual processor) that manipulates data values according to control signals (e.g., "commands", "op codes", "machine code", etc.) and which produces corresponding output signals that are applied to operate a machine. A processor may, for example, be a Central Processing Unit (CPU), a Reduced Instruction Set Computing (RISC) processor, a Complex Instruction Set Computing (CISC) processor, a Graphics Processing Unit (GPU), a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Radio-Frequency Integrated Circuit (RFIC) or any combination thereof. A processor may further be a multi-core processor having two or more independent processors (sometimes referred to as "cores") that may execute instructions contemporaneously.

Accordingly, the phrase "hardware component" (or "hardware-implemented component") should be understood to encompass a tangible entity, be that an entity that is physically constructed, permanently configured (e.g., hardwired), or temporarily configured (e.g., programmed) to operate in a certain manner or to perform certain operations described herein. Considering embodiments in which hardware components are temporarily configured (e.g., programmed), each of the hardware components need not be configured or instantiated at any one instance in time. For example, where a hardware component comprises a general-purpose processor configured by software to become a special-purpose processor, the general-purpose processor may be configured as respectively different special-purpose processors (e.g., comprising different hardware components) at different times. Software accordingly configures a particular processor or processors, for example, to constitute a particular hardware component at one instance of time and to constitute a different hardware component at a different instance of time. Hardware components can provide information to, and receive information from, other hardware components. Accordingly, the described hardware components may be regarded as being communicatively coupled. Where multiple hardware components exist contemporaneously, communications may be achieved through signal transmission (e.g., over appropriate circuits and buses) between or among two or more of the hardware components. In embodiments in which multiple hardware components are configured or instantiated at different times, communications between such hardware components may be achieved, for example, through the storage and retrieval of information in memory structures to which the multiple hardware components have access.

For example, one hardware component may perform an operation and store the output of that operation in a memory device to which it is communicatively coupled. A further hardware component may then, at a later time, access the memory device to retrieve and process the stored output. Hardware components may also initiate communications with input or output devices, and can operate on a resource (e.g., a collection of information). Whether temporarily or permanently configured, such processors may constitute processor-implemented components that operate to perform one or more operations or functions described herein. As used herein, "processor-implemented component" refers to a hardware component implemented using one or more processors. Similarly, the methods described herein may be at least partially processor-implemented, with a particular processor or processors being an example of hardware. For example, at least some of the operations of a method may be performed by one or more processors or processor-implemented components.

For example, at least some of the operations may be performed by a group of computers (as examples of machines including processors), with these operations being accessible via a network (e.g., the Internet) and via one or more appropriate interfaces (e.g., an Application Program Interface (API)). The performance of certain of the operations may be distributed among the processors, not only residing within a single machine, but deployed across a number of machines. In some exemplary embodiments, the processors or processor-implemented components may be located in a single geographic location (e.g., within a home environment, an office environment, or a server farm). In other exemplary embodiments, the processors or processor-implemented components may be distributed across a number of geographic locations.

In the exemplary architecture of <FIG>, the software architecture <NUM> may be conceptualized as a stack of layers where each layer provides particular functionality. For example, the software architecture <NUM> may include layers such as an operating system <NUM>, libraries <NUM>, applications <NUM> and a presentation layer <NUM>. Operationally, the applications <NUM> or other components within the layers may invoke application programming interface (API) API calls <NUM> through the software stack and receive messages <NUM> in response to the API calls <NUM>. The layers illustrated are representative in nature and not all software architectures have all layers. For example, some mobile or special purpose operating systems may not provide a frameworks/middleware <NUM>, while others may provide such a layer. Other software architectures may include additional or different layers.

The operating system <NUM> may manage hardware resources and provide common services. The operating system <NUM> may include, for example, a kernel <NUM>, services <NUM> and drivers <NUM>. The kernel <NUM> may act as an abstraction layer between the hardware and the other software layers. For example, the kernel <NUM> may be responsible for memory management, processor management (e.g., scheduling), component management, networking, security settings, and so on. The drivers <NUM> are responsible for controlling or interfacing with the underlying hardware. For instance, the drivers <NUM> include display drivers, camera drivers, Bluetooth® drivers, flash memory drivers, serial communication drivers (e.g., Universal Serial Bus (USB) drivers), Wi-Fi® drivers, audio drivers, power management drivers, and so forth depending on the hardware configuration.

The libraries <NUM> provide a common infrastructure that is used by the applications <NUM> or other components or layers. The libraries <NUM> provide functionality that allows other software components to perform tasks in an easier fashion than to interface directly with the underlying operating system <NUM> functionality (e.g., kernel <NUM>, services <NUM> or drivers <NUM>). The libraries <NUM> may include system libraries <NUM> (e.g., C standard library) that may provide functions such as memory allocation functions, string manipulation functions, mathematical functions, and the like. In addition, the libraries <NUM> may include API libraries <NUM> such as media libraries (e.g., libraries to support presentation and manipulation of various media format such as MPREG4, H. <NUM>, MP3, AAC, AMR, JPG, PNG), graphics libraries (e.g., an OpenGL framework that may be used to render 2D and 3D in a graphic content on a display), database libraries (e.g., SQLite that may provide various relational database functions), web libraries (e.g., WebKit that may provide web browsing functionality), and the like. The libraries <NUM> may also include a wide variety of other libraries <NUM> to provide many other APIs to the applications <NUM> and other software components/modules.

The frameworks/middleware <NUM> (also sometimes referred to as middleware) provide a higher-level common infrastructure that may be used by the applications <NUM> or other software components/modules. For example, the frameworks/middleware <NUM> may provide various graphic user interface (GUI) functions, high-level resource management, high-level location services, and so forth. The frameworks/middleware <NUM> may provide a broad spectrum of other APIs that may be utilized by the applications <NUM> or other software components/modules, some of which may be specific to a particular operating system <NUM> or platform.

The applications <NUM> include built-in applications <NUM> or third-party applications <NUM>. Examples of representative built-in applications <NUM> may include, but are not limited to, a contacts application, a browser application, a book reader application, a location application, a media application, a messaging application, or a game application. Third-party applications <NUM> may include an application developed using software development kit (SDK) by an entity other than the vendor of the particular platform and may be mobile software running on a mobile operating system. The third-party applications <NUM> may invoke the API calls <NUM> provided by the mobile operating system (such as operating system <NUM>) to facilitate functionality described herein.

The applications <NUM> may use built in operating system functions (e.g., kernel <NUM>, services <NUM> or drivers <NUM>), libraries <NUM>, and frameworks/middleware <NUM> to create user interfaces to interact with users of the system. Alternatively, or additionally, in some systems interactions with a user may occur through a presentation layer, such as presentation layer <NUM>. In these systems, the application/component "logic" can be separated from the aspects of the application/component that interact with a user.

<FIG> is a block diagram illustrating components (also referred to herein as "modules") of a machine <NUM>, according to some exemplary embodiments, able to read instructions from a machine-readable medium (e.g., a machine-readable storage medium) and perform any one or more of the methodologies discussed herein. Specifically, <FIG> shows a diagrammatic representation of the machine <NUM> in the example form of a computer system, within which instructions <NUM> (e.g., software, a program, an application, an applet, an app, or other executable code) for causing the machine <NUM> to perform any one or more of the methodologies discussed herein may be executed. As such, the instructions <NUM> may be used to implement modules or components described herein. The instructions <NUM> transform the general, non-programmed machine <NUM> into a particular machine <NUM> programmed to carry out the described and illustrated functions in the manner described. In alternative embodiments, the machine <NUM> operates as a standalone device or may be coupled (e.g., networked) to other machines. In a networked deployment, the machine <NUM> may operate in the capacity of a server machine or a client machine in a server-client network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine <NUM> may comprise, but not be limited to, a server computer, a client computer, a personal computer (PC), a tablet computer, a laptop computer, a netbook, a set-top box (STB), a personal digital assistant (PDA), an entertainment media system, a cellular telephone, a smart phone, a mobile device, a wearable device (e.g., a smart watch), a smart home device (e.g., a smart appliance), other smart devices, a web appliance, a network router, a network switch, a network bridge, or any machine capable of executing the instructions <NUM>, sequentially or otherwise, that specify actions to be taken by machine <NUM>. Further, while only a single machine <NUM> is illustrated, the term "machine" shall also be taken to include a collection of machines that individually or jointly execute the instructions <NUM> to perform any one or more of the methodologies discussed herein.

The machine <NUM> may include processors <NUM>, memory memory/storage <NUM>, and I/O components <NUM>, which may be configured to communicate with each other such as via a bus <NUM>. The memory/storage <NUM> may include a memory <NUM>, such as a main memory, or other memory storage, and a storage unit <NUM>, both accessible to the processors <NUM> such as via the bus <NUM>. The storage unit <NUM> and memory <NUM> store the instructions <NUM> embodying any one or more of the methodologies or functions described herein. The instructions <NUM> may also reside, completely or partially, within the memory <NUM>, within the storage unit <NUM>, within at least one of the processors <NUM> (e.g., within the processor's cache memory), or any suitable combination thereof, during execution thereof by the machine <NUM>. Accordingly, the memory <NUM>, the storage unit <NUM>, and the memory of processors <NUM> are examples of machine-readable media.

As used herein, the term "machine-readable medium," "computer-readable medium," or the like may refer to any component, device or other tangible media able to store instructions and data temporarily or permanently. Examples of such media may include, but is not limited to, random-access memory (RAM), read-only memory (ROM), buffer memory, flash memory, optical media, magnetic media, cache memory, other types of storage (e.g., Erasable Programmable Read-Only Memory (EEPROM)) or any suitable combination thereof. The term "machine-readable medium" should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, or associated caches and servers) able to store instructions. The term "machine-readable medium" may also be taken to include any medium, or combination of multiple media, that is capable of storing instructions (e.g., code) for execution by a machine, such that the instructions, when executed by one or more processors of the machine, cause the machine to perform any one or more of the methodologies described herein. Accordingly, a "machine-readable medium" may refer to a single storage apparatus or device, as well as "cloud-based" storage systems or storage networks that include multiple storage apparatus or devices. The term "machine-readable medium" excludes signals per se.

The I/O components <NUM> may include a wide variety of components to provide a user interface for receiving input, providing output, producing output, transmitting information, exchanging information, capturing measurements, and so on. The specific I/O components <NUM> that are included in the user interface of a particular machine <NUM> will depend on the type of machine. For example, portable machines such as mobile phones will likely include a touch input device or other such input mechanisms, while a headless server machine will likely not include such a touch input device. It will be appreciated that the I/O components <NUM> may include many other components that are not shown in <FIG>. The I/O components <NUM> are grouped according to functionality merely for simplifying the following discussion and the grouping is in no way limiting. In various exemplary embodiments, the I/O components <NUM> may include output components <NUM> and input components <NUM>. The output components <NUM> may include visual components (e.g., a display such as a plasma display panel (PDP), a light emitting diode (LED) display, a liquid crystal display (LCD), a projector, or a cathode ray tube (CRT)), acoustic components (e.g., speakers), haptic components (e.g., a vibratory motor, resistance mechanisms), other signal generators, and so forth. The input components <NUM> may include alphanumeric input components (e.g., a keyboard, a touch screen configured to receive alphanumeric input, a photo-optical keyboard, or other alphanumeric input components), point based input components (e.g., a mouse, a touchpad, a trackball, a joystick, a motion sensor, or other pointing instrument), tactile input components (e.g., a physical button, a touch screen that provides location or force of touches or touch gestures, or other tactile input components), audio input components (e.g., a microphone), and the like. The input components <NUM> may also include one or more image-capturing devices, such as a digital camera for generating digital images or video.

In further exemplary embodiments, the I/O components <NUM> may include biometric components <NUM>, motion components <NUM>, environmental environment components <NUM>, or position components <NUM>, as well as a wide array of other components. One or more of such components (or portions thereof) may collectively be referred to herein as a "sensor component" or "sensor" for collecting various data related to the machine <NUM>, the environment of the machine <NUM>, a user of the machine <NUM>, or a combination thereof.

For example, the biometric components <NUM> may include components to detect expressions (e.g., hand expressions, facial expressions, vocal expressions, body gestures, or eye tracking), measure biosignals (e.g., blood pressure, heart rate, body temperature, perspiration, or brain waves), identify a person (e.g., voice identification, retinal identification, facial identification, fingerprint identification, or electroencephalogram-based identification), and the like. The motion components <NUM> may include acceleration sensor components (e.g., accelerometer), gravitation sensor components, velocity sensor components (e.g., speedometer), rotation sensor components (e.g., gyroscope), and so forth. The environment components <NUM> may include, for example, illumination sensor components (e.g., photometer), temperature sensor components (e.g., one or more thermometer that detect ambient temperature), humidity sensor components, pressure sensor components (e.g., barometer), acoustic sensor components (e.g., one or more microphones that detect background noise), proximity sensor components (e.g., infrared sensors that detect nearby objects), gas sensors (e.g., gas detection sensors to detection concentrations of hazardous gases for safety or to measure pollutants in the atmosphere), or other components that may provide indications, measurements, or signals corresponding to a surrounding physical environment. The position components <NUM> may include location sensor components (e.g., a Global Position system (GPS) receiver component), altitude sensor components (e.g., altimeters or barometers that detect air pressure from which altitude may be derived), orientation sensor components (e.g., magnetometers), and the like. For example, the location sensor component may provide location information associated with the system <NUM>, such as the system's <NUM> GPS coordinates or information regarding a location the system <NUM> is at currently (e.g., the name of a restaurant or other business).

Communication may be implemented using a wide variety of technologies. The I/O components <NUM> may include communication components <NUM> operable to couple the machine <NUM> to a network <NUM> or devices <NUM> via coupling <NUM> and coupling <NUM> respectively. For example, the communication components <NUM> may include a network interface component or other suitable device to interface with the network <NUM>. In further examples, communication components <NUM> may include wired communication components, wireless communication components, cellular communication components, Near Field Communication (NFC) components, Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components, and other communication components to provide communication via other modalities. The devices <NUM> may be another machine or any of a wide variety of peripheral devices (e.g., a peripheral device coupled via a Universal Serial Bus (USB)).

In addition, a variety of information may be derived via the communication components <NUM>, such as, location via Internet Protocol (IP) geo-location, location via Wi-Fi® signal triangulation, location via detecting an NFC beacon signal that may indicate a particular location, and so forth.

<FIG> is a high-level functional block diagram of an example head-wearable apparatus <NUM> communicatively coupled a mobile device <NUM> and a server system <NUM> via various networks.

Apparatus <NUM> includes a camera, such as at least one of visible light camera <NUM>, infrared emitter <NUM> and infrared camera <NUM>. The camera can include the camera module with the lens 104_1, 104_2 in <FIG>.

Client device <NUM> can be capable of connecting with apparatus <NUM> using both a low-power wireless connection <NUM> and a high-speed wireless connection <NUM>. Client device <NUM> is connected to server system <NUM> and network <NUM>. The network <NUM> may include any combination of wired and wireless connections.

Apparatus <NUM> further includes two image displays of the optical assembly 980A-B. The two image displays 980A-980B include one associated with the left lateral side and one associated with the right lateral side of the apparatus <NUM>. Apparatus <NUM> also includes image display driver <NUM>, image processor <NUM>, low-power circuitry <NUM>, and high-speed circuitry <NUM>. Image display of optical assembly 980A-B are for presenting images and videos, including an image that can include a graphical user interface to a user of the apparatus <NUM>.

Image display driver <NUM> commands and controls the image display of the optical assembly 980A-B. Image display driver <NUM> may deliver image data directly to the image display of the optical assembly 980A-B for presentation or may have to convert the image data into a signal or data format suitable for delivery to the image display device. For example, the image data may be video data formatted according to compression formats, such as H. <NUM> (MPEG-<NUM> Part <NUM>), HEVC, Theora, Dirac, Real Video RV40, VP8, VP9, or the like, and still image data may be formatted according to compression formats such as Portable Network Group (PNG), Joint Photographic Experts Group (JPEG), Tagged Image File Format (TIFF) or exchangeable image file format (Exif) or the like.

As noted above, apparatus <NUM> includes a frame <NUM> and stems (or temples) extending from a lateral side of the frame <NUM>. Apparatus <NUM> further includes a user input device <NUM> (e.g., touch sensor or push button) including an input surface on the apparatus <NUM>. The user input device <NUM> (e.g., touch sensor or push button) is to receive from the user an input selection to manipulate the graphical user interface of the presented image.

The components shown in <FIG> for the apparatus <NUM> are located on one or more circuit boards, for example a PCB or flexible PCB, in the rims or temples. Alternatively or additionally, the depicted components can be located in the chunks, frames, hinges, or bridge of the apparatus <NUM>. Left and right visible light cameras <NUM> can include digital camera elements such as a complementary metal-oxide-semiconductor (CMOS) image sensor, charge coupled device, a lens 104_1, 104_2, or any other respective visible or light capturing elements that may be used to capture data, including images of scenes with unknown objects.

Apparatus <NUM> includes a memory <NUM> which stores instructions to perform a subset or all of the functions described herein for generating binatiral audio content. Memory <NUM> can also include storage device <NUM>. The exemplary process illustrated in the flowchart in <FIG> can be implemented in instructions stored in memory <NUM>.

As shown in <FIG>, high-speed circuitry <NUM> includes high-speed processor <NUM>, memory <NUM>, and high-speed wireless circuitry <NUM>. In the example, the image display driver <NUM> is coupled to the high-speed circuitry <NUM> and operated by the high-speed processor <NUM> in order to drive the left and right image displays of the optical assembly 980A-B. High-speed processor <NUM> may be any processor capable of managing high-speed communications and operation of any general computing system needed for apparatus <NUM>. High-speed processor <NUM> includes processing resources needed for managing high-speed data transfers on high-speed wireless connection <NUM> to a wireless local area network (WLAN) using high-speed wireless circuitry <NUM>. In certain examples, the high-speed processor <NUM> executes an operating system such as a LINUX operating system or other such operating system of the apparatus <NUM> and the operating system is stored in memory <NUM> for execution. In addition to any other responsibilities, the high-speed processor <NUM> executing a software architecture for the apparatus <NUM> is used to manage data transfers with high-speed wireless circuitry <NUM>. In certain examples, high-speed wireless circuitry <NUM> is configured to implement Institute of Electrical and Electronic Engineers (IEEE) <NUM> communication standards, also referred to herein as Wi-Fi. In other examples, other high-speed communications standards may be implemented by high-speed wireless circuitry <NUM>.

Low-power wireless circuitry <NUM> and the high-speed wireless circuitry <NUM> of the apparatus <NUM> can include short range transceivers (Bluetooth™) and wireless wide, local, or wide area network transceivers (e.g., cellular or WiFi). Client device <NUM>, including the transceivers communicating via the low-power wireless connection <NUM> and high-speed wireless connection <NUM>, may be implemented using details of the architecture of the apparatus <NUM>, as can other elements of network <NUM>.

Memory <NUM> includes any storage device capable of storing various data and applications, including, among other things, camera data generated by the left and right visible light cameras <NUM>, infrared camera <NUM>, and the image processor <NUM>, as well as images generated for display by the image display driver <NUM> on the image displays of the optical assembly 980A-B. While memory <NUM> is shown as integrated with high-speed circuitry <NUM>, in other examples, memory <NUM> may be an independent standalone element of the apparatus <NUM>. In certain such examples, electrical routing lines may provide a connection through a chip that includes the high-speed processor <NUM> from the image processor <NUM> or low-power processor <NUM> to the memory <NUM>. In other examples, the high-speed processor <NUM> may manage addressing of memory <NUM> such that the low-power processor <NUM> will boot the high-speed processor <NUM> any time that a read or write operation involving memory <NUM> is needed.

As shown in <FIG>, the processor <NUM> of the apparatus <NUM> can be coupled to the camera (visible light cameras <NUM>; infrared emitter <NUM><NUM>, or infrared camera <NUM>), the image display driver <NUM>, the user input device <NUM> (e.g., touch sensor or push button), and the memory <NUM>.

Apparatus <NUM> is connected with a host computer. For example, the apparatus <NUM> is paired with the client device <NUM> via the high-speed wireless connection <NUM> or connected to the server system <NUM> via the network <NUM>. Server system <NUM> may be one or more computing devices as part of a service or network computing system, for example, that include a processor, a memory, and network communication interface to communicate over the network <NUM> with the client device <NUM> and apparatus <NUM>.

The client device <NUM> includes a processor and a network communication interface coupled to the processor. The network communication interface allows for communication over the network <NUM> or <NUM>. Client device <NUM> can further store at least portions of the instructions for generating a binaural audio content in the client device <NUM>'s memory to implement the functionality described herein.

Output components of the apparatus <NUM> include visual components, such as a display such as a liquid crystal display (LCD), a plasma display panel (PDP), a light emitting diode (LED) display, a projector, or a waveguide. The image displays of the optical assembly are driven by the image display driver <NUM>. The output components of the apparatus <NUM> further include acoustic components (e.g., speakers), haptic components (e.g., a vibratory motor), other signal generators, and so forth. The input components of the apparatus <NUM>, the client device <NUM>, and server system <NUM>, such as the user input device <NUM>, may include alphanumeric input components (e.g., a keyboard, a touch screen configured to receive alphanumeric input, a photo-optical keyboard, or other alphanumeric input components), point-based input components (e.g., a mouse, a touchpad, a trackball, a joystick, a motion sensor, or other pointing instruments), tactile input components (e.g., a physical button, a touch screen that provides location and force of touches or touch gestures, or other tactile input components), audio input components (e.g., a microphone), and the like.

Apparatus <NUM> may optionally include additional peripheral device elements. Such peripheral device elements may include biometric sensors, additional sensors, or display elements integrated with apparatus <NUM>. For example, peripheral device elements may include any I/O components including output components, motion components, position components, or any other such elements described herein.

For example, the biometric components include components to detect expressions (e.g., hand expressions, facial expressions, vocal expressions, body gestures, or eye tracking), measure biosignals (e.g., blood pressure, heart rate, body temperature, perspiration, or brain waves), identify a person (e.g., voice identification, retinal identification, facial identification, fingerprint identification, or electroencephalogram based identification), and the like. The motion components include acceleration sensor components (e.g., accelerometer), gravitation sensor components, rotation sensor components (e.g., gyroscope), and so forth. The position components include location sensor components to generate location coordinates (e.g., a Global Positioning System (GPS) receiver component), WiFi or Bluetooth™ transceivers to generate positioning system coordinates, altitude sensor components (e.g., altimeters or barometers that detect air pressure from which altitude may be derived), orientation sensor components (e.g., magnetometers), and the like. Such positioning system coordinates can also be received over wireless connections <NUM> and <NUM> from the client device <NUM> via the low-power wireless circuitry <NUM> or high-speed wireless circuitry <NUM>.

Where a phrase similar to "at least one of A, B, or C," "at least one of A, B, and C," "one or more A, B, or C," or "one or more of A, B, and C" is used, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B and C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C.

Claim 1:
A head-wearable apparatus (<NUM>) comprising:
a frame (<NUM>);
a first stem coupled to a first side of the frame and to a first microphone housing (101_1) that encases a first front microphone (110_3) and a first rear microphone (110_4) that generate acoustic signals, respectively, the first microphone housing (101_1) includes a first front port that faces downward and a first rear port that faces backwards,
a second stem coupled to a second side of the frame and to a second microphone housing (101_2) that encases a second front microphone (110_1) and a second rear microphone (110_2) that generate acoustic signals, respectively, the second microphone housing (101_2) includes a second front port that faces downward and a second rear port that faces backwards; and
a binaural audio processor (<NUM>) that includes
a beamformer (<NUM>) to receive the acoustic signals from the first front microphone (110_3), the first rear microphone (110_4), the second front microphone (110_1) and the second rear microphone (110_2) and to generate
a first beamformer signal based on the acoustic signals from the first front microphone and the first rear microphone, and
a second beamformer signal based on the acoustic signals from the second front microphone and the second rear microphone, and
a storage device (<NUM>) to store the first beamformer signal and the second beamformer signal as a two-channel file.