Emphasis for audio spatialization

Abstract

Examples of the present disclosure describe systems and methods for presenting an audio signal to a user of a wearable head device. According to the example method, a first input audio signal is received. The first input audio signal is processed to generate a first output audio signal. The first output audio signal is presented via one or more speakers associated with the wearable head device. Processing the first input audio signal includes applying a pre-emphasis filter to the first input audio signal; adjusting a gain of the first input audio signal; and applying a de-emphasis filter to the first audio signal. Applying the pre-emphasis filter to the first input audio signal includes attenuating low-frequency components of the first input audio signal. Applying the de-emphasis filter to the first input audio signal includes attenuating high-frequency components of the first input audio signal.

Description

[0001] This application is a divisional application of an application with an application date of October 4, 2019, PCT international application number of PCT / US2019 / 054894, Chinese national phase application number of 201980080266.2, and invention name of “Emphasis for Audio Spatialization”.

[0002] Citation of Related Applications

[0003] This application claims the benefit of priority to U.S. Provisional Application No. 62 / 742,254 filed on October 5, 2018, U.S. Provisional Application No. 62 / 812,546 filed on March 1, 2019, and U.S. Provisional Application No. 62 / 742,191 filed on October 5, 2018, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0004] The present disclosure relates generally to systems and methods for audio signal processing, and more particularly, to systems and methods for presenting audio signals in a mixed reality environment. Background Art

[0005] Immersive and credible virtual environments require that audio signals be presented in a manner consistent with the user's expectations - for example, that the audio signals corresponding to objects in the virtual environment will be consistent with the object's position in the virtual environment and the visual presentation of the object. Creating rich and complex soundscapes (sound environments) in virtual reality, augmented reality, and mixed reality environments requires efficient presentation of a large number of digital audio signals, each of which appears to come from a different position / proximity and / or direction in the user's environment. The soundscape includes the presentation of objects and is relative to the user; the position and orientation of objects and users can change rapidly, requiring the soundscape to be adjusted accordingly. Adjusting the soundscape to credibly reflect the position and orientation of objects and users may require rapid changes to the audio signal, which may result in undesirable sonic artifacts, such as "click" sounds, which impair the immersion of the virtual environment. However, some techniques for reducing such sonic artifacts may be computationally expensive, particularly for mobile devices that are typically used to interact with virtual environments. It is desirable to present a soundscape to a user of a virtual environment to accurately reflect the sound of the virtual environment while minimizing sonic artifacts and maintaining a computationally efficient system and method. Summary of the invention

[0006] Examples of the present disclosure describe systems and methods for presenting an audio signal to a user of a wearable head device. According to the example method, a first input audio signal is received. The first input audio signal is processed to generate a first output audio signal. The first output audio signal is presented via one or more speakers associated with the wearable head device. Processing the first input audio signal includes applying a pre-emphasis filter to the first input audio signal; adjusting a gain of the first input audio signal; and applying a de-emphasis filter to the first audio signal. Applying the pre-emphasis filter to the first input audio signal includes attenuating low-frequency components of the first input audio signal. Applying the de-emphasis filter to the first input audio signal includes attenuating high-frequency components of the first input audio signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1A-1B An example audio spatialization system is shown in accordance with some embodiments of the present disclosure.

[0008] Figures 2A-2H An example audio spatialization system is shown in accordance with some embodiments of the present disclosure.

[0009] Figure 3A An example audio spatialization system including a pre-emphasis filter and a de-emphasis filter according to some embodiments of the present disclosure is shown.

[0010] Figure 3B An example pre-emphasis filter according to some embodiments of the present disclosure is shown.

[0011] Figure 3C An example de-emphasis filter according to some embodiments of the present disclosure is shown.

[0012] Figure 4-8 An example audio spatialization system including a pre-emphasis filter and a de-emphasis filter according to some embodiments of the present disclosure is shown.

[0013] Fig. 9 An example wearable system according to some embodiments of the present disclosure is shown.

[0014] Fig.10 An example handheld controller is shown that may be used in conjunction with an example wearable system in accordance with some embodiments of the present disclosure.

[0015] Fig.11 An example auxiliary unit is shown that may be used in conjunction with an example wearable system according to some embodiments of the present disclosure.

[0016] Fig.12 An example functional block diagram for an example wearable system according to some embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0017] In the following example description, reference is made to the accompanying drawings which form a part hereof and in which are shown by way of illustration specific examples that can be practiced. It should be understood that other examples can be used and structural changes can be made without departing from the scope of the disclosed examples.

[0018] Example Wearable System

[0019] Fig. 9An example wearable head device 900 is shown, which is configured to be worn on a user's head. Wearable head device 900 can be part of a broader wearable system that includes one or more components, such as a head device (e.g., wearable head device 900), a handheld controller (e.g., handheld controller 1000 described below), and / or an auxiliary unit (e.g., auxiliary unit 1100 described below). In some examples, wearable head device 900 can be used in virtual reality, augmented reality, or mixed reality systems or applications. The wearable head device 900 may include one or more displays, such as displays 910A and 910B (which may include left and right transmissive displays and associated components for coupling light from the displays to the user's eyes, such as orthogonal pupil expansion (OPE) grating groups 912A / 912B and exit pupil expansion (EPE) grating groups 914A / 914B); left and right acoustic structures, such as speakers 920A and 920B (which may be mounted on temples 922A and 922B and located near the user's left and right ears, respectively); one or more sensors, such as an infrared sensor, an accelerometer, a GPS unit, an inertial measurement unit (IMU, for example, an IMU 926), an acoustic sensor (e.g., microphone 950); an orthogonal coil electromagnetic receiver (e.g., receiver 927 shown mounted to the left temple 922A); left and right cameras oriented away from the user (e.g., depth (time of flight) cameras 930A and 930B); and left and right eye cameras oriented toward the user (e.g., for detecting eye movements of the user) (e.g., eye cameras 928A and 928B). However, without departing from the scope of the present disclosure, the wearable head device 900 may incorporate any suitable display technology and any suitable number, type, or combination of sensors or other components. In some examples, the wearable head device 900 may incorporate one or more microphones 950 configured to detect audio signals generated by the user's voice; such microphones may be placed adjacent to the user's mouth. In some examples, the wearable head device 900 may incorporate networking features (e.g., Wi-Fi functionality) to communicate with other devices and systems including other wearable systems. The wearable head device 900 may also include components such as a battery, a processor, a memory, a storage unit, or various input devices (e.g., buttons, touch pads); or may be coupled to a handheld controller (e.g., handheld controller 1000) or an auxiliary unit (e.g., auxiliary unit 1100) including one or more such components. In some examples, the sensor may be configured to output a set of coordinates of the head-mounted unit relative to the user's environment and may provide input to a processor that performs a simultaneous localization and mapping (SLAM) process and / or visual odometry.In some examples, wearable head unit 900 can be coupled to handheld controller 1000 and / or auxiliary unit 1100, as further described below.

[0020] Fig.10 An example mobile handheld controller assembly 1000 of an example wearable system is shown. In some examples, the handheld controller 1000 can communicate with the wearable head device 900 and / or the auxiliary unit 1100 described below in wired or wireless communication. In some examples, the handheld controller 1000 includes a handle portion 1020 to be held by a user and one or more buttons 1040 disposed along a top surface 1010. In some examples, the handheld controller 1000 can be configured to be used as an optical tracking target; for example, a sensor (e.g., a camera or other optical sensor) of the wearable head device 900 can be configured to detect the position and / or orientation of the handheld controller 1000—by extension, this can indicate the position and / or orientation of the hand of the user holding the handheld controller 1000. In some examples, the handheld controller 1000 can include a processor, a memory, a storage unit, a display, or one or more input devices, such as described above. In some examples, the handheld controller 1000 includes one or more sensors (e.g., any sensor or tracking component described above with respect to the wearable head device 900). In some examples, the sensor can detect the position or orientation of the handheld controller 1000 relative to the wearable head device 900 or relative to another component of the wearable system. In some examples, the sensor can be positioned in the handle portion 1020 of the handheld controller 1000 and / or can be mechanically coupled to the handheld controller. The handheld controller 1000 can be configured to provide one or more output signals, for example, a signal corresponding to the pressed state of the button 1040; or the position, orientation and / or movement of the handheld controller 1000 (for example, through an IMU). Such output signals can be used as inputs to a processor of the wearable head device 900, the auxiliary unit 1100, or another component of the wearable system. In some examples, the handheld controller 1000 can include one or more microphones to detect sounds (e.g., the user's voice, ambient sounds) and in some cases to provide signals corresponding to the detected sounds to a processor (e.g., a processor of the wearable head device 900).

[0021] Fig.11An example auxiliary unit 1100 of an example wearable system is shown. In some examples, the auxiliary unit 1100 can communicate with the wearable head device 900 and / or the handheld controller 1000 in wired or wireless communication. The auxiliary unit 1100 can include a battery to provide energy to operate one or more components of the wearable system, such as the wearable head device 900 and / or the handheld controller 1000 (including a display, a sensor, an acoustic structure, a processor, a microphone, and / or other components of the wearable head device 900 or the handheld controller 1000). In some examples, the auxiliary unit 1100 may include a processor, a memory, a storage unit, a display, one or more input devices, and / or one or more sensors, such as described above. In some examples, the auxiliary unit 1100 includes a clip 1110 for attaching the auxiliary unit to a user (e.g., a belt worn by the user). An advantage of using auxiliary unit 1100 to house one or more components of the wearable system is that doing so can allow large or heavy components to be carried on the user's waist, chest, or back—which are relatively well suited for supporting large and heavy objects—rather than being mounted to the user's head (e.g., if housed in wearable head device 900) or carried by the user's hand (e.g., if housed in handheld controller 1000). This can be particularly advantageous for relatively heavy or bulky components, such as batteries.

[0022] Fig.12 1 shows an example functional block diagram that may correspond to an example wearable system 1200, such as may include the example wearable head device 900, handheld controller 1000, and auxiliary unit 1100 described above. In some examples, the wearable system 1200 may be used for virtual reality, augmented reality, or mixed reality applications. Fig.12As shown, the wearable system 1200 may include an example handheld controller 1200B, referred to herein as a "totem" (and which may correspond to the handheld controller 1000 described above); the handheld controller 1200B may include a totem-to-headgear six-degree-of-freedom (6DOF) totem subsystem 1204A. The wearable system 1200 may also include an example headgear assembly 1200A (which may correspond to the wearable headgear 900 described above); the headgear assembly 1200A includes a totem-to-headgear 6DOF headgear subsystem 1204B. In this example, the 6DOF totem subsystem 1204A and the 6DOF headgear subsystem 1204B cooperate to determine six coordinates of the handheld controller 1200B relative to the headgear assembly 1200A (e.g., offsets in three translational directions and rotations along three axes). The six degrees of freedom may be expressed relative to the coordinate system of the headgear assembly 1200A. The three translation offsets may be represented as X, Y, and Z offsets in such a coordinate system, may be represented as a translation matrix, or may be represented as some other representation. The rotational degrees of freedom may be represented as a sequence of yaw, pitch, and roll rotations; as a vector; as a rotation matrix; as a quaternion; or as some other representation. In some examples, one or more depth cameras 1244 (and / or one or more non-depth cameras) and / or one or more optical targets (e.g., a button 1040 of the handheld controller 1000 as described above or a dedicated optical target included in the handheld controller) included in the head device apparatus 1200A may be used for 6DOF tracking. In some examples, as described above, the handheld controller 1200B may include a camera; and the head device apparatus 1200A may include an optical target for optical tracking in combination with the camera. In some examples, each of the head device apparatus 1200A and the handheld controller 1200B includes a set of three orthogonally oriented solenoids for wirelessly sending and receiving three distinguishable signals. By measuring the relative amplitudes of the three distinguishable signals received in each coil used for reception, the 6DOF of the handheld controller 1200B relative to the head device assembly 1200A can be determined. In some examples, the 6DOF totem subsystem 1204A can include an inertial measurement unit (IMU) that can be used to provide improved accuracy and / or more timely information about rapid movements of the handheld controller 1200B.

[0023] In some examples involving augmented reality or mixed reality applications, it may be desirable to transform coordinates from a local coordinate space (e.g., a coordinate space that is fixed relative to the head device apparatus 1200A) to an inertial coordinate space or an environmental coordinate system coordination space. For example, such a transformation may be necessary for the display of the head device apparatus 1200A to present a virtual object (e.g., a virtual person sitting in a real chair, facing forward, regardless of the position and orientation of the head device apparatus 1200A) at an expected position and orientation relative to the real environment rather than at a fixed position and orientation on the display (e.g., at the same position in the display of the head device apparatus 1200A). This can maintain the illusion that the virtual object exists in the real environment (and, for example, will not appear to be positioned unnaturally in the real environment as the head device apparatus 1200A moves and rotates). In some examples, compensating transformations between coordinate spaces can be determined by processing images from the depth camera 1244 (e.g., using simultaneous localization and mapping (SLAM) and / or visual odometry processes) to determine the transformation of the head device apparatus 1200A relative to the inertial or environmental coordinate system. In Fig.12 In the example shown, the depth camera 1244 can be coupled to the SLAM / visual odometry box 1206 and can provide images to the box 1206. The SLAM / visual odometry box 1206 implementation may include a processor configured to process the image and determine the position and orientation of the user's head, which can then be used to identify the transformation between the head coordinate space and the actual coordinate space. Similarly, in some examples, an additional source of information about the user's head posture and position is obtained from the IMU 1209 of the head device device 1200A. Information from the IMU 1209 can be integrated with information from the SLAM / visual odometry box 1206 to provide improved accuracy and / or more timely information for rapid adjustment of the user's head posture and position.

[0024] In some examples, the depth camera 1244 can provide the 3D image to the hand gesture tracker 1211, which can be implemented in a processor of the wearable head device 1200A. The hand gesture tracker 1211 can recognize the user's hand gestures, for example, by matching the 3D image received from the depth camera 1244 with a stored pattern representing a hand gesture. Other suitable techniques for recognizing the user's hand gestures will be apparent.

[0025] In some examples, one or more processors 1216 can be configured to receive data from the head device subsystem 1204B, the IMU 1209, the SLAM / visual odometer box 1206, the depth camera 1244, the microphone 1250, and / or the hand gesture tracker 1211. The processor 1216 can also send and receive control signals from the 6DOF totem system 1204A. The processor 1216 can be wirelessly coupled to the 6DOF totem system 1204A, for example in an example where the handheld controller 1200B is not limited. The processor 1216 can further communicate with additional components such as an audio-visual content memory 1218, a graphics processing unit (GPU) 1220, and / or a digital signal processor (DSP) audio sound field localizer 1222. The DSP audio sound field localizer 1222 can be coupled to a head-related transfer function (HRTF) memory 1225. The GPU 1220 may include a left channel output of a left source 1224 coupled to an imaging light modulator and a right channel output of a right source 1226 coupled to the imaging light modulator. The GPU 1220 may output stereoscopic image data to the sources 1224, 1226 of the imaging light modulator. The DSP audio sound field localizer 1222 may output audio to the left speaker 1212 and / or the right speaker 1214. The DSP audio sound field localizer 1222 may receive an input from the processor 1216 indicating a direction vector of a vector from a user to a virtual sound source (which may be moved by the user, for example, via a handheld controller 1200B). Based on the direction vector, the DSP audio sound field localizer 1222 may determine a corresponding HRTF (e.g., by accessing the HRTF or by interpolating multiple HRTFs). Then, the DSP audio sound field localizer 1222 may apply the determined HRTF to an audio signal, such as an audio signal corresponding to a virtual sound generated by a virtual object. By incorporating the user's relative position and orientation with respect to virtual sounds in a mixed reality environment—that is, by presenting virtual sounds that match the user's expectations of how the virtual sounds would sound like real sounds in a real environment—the credibility and realism of the virtual sounds can be enhanced.

[0026] In some examples, such as Fig.12As shown in , one or more of the processor 1216, GPU 1220, DSP audio sound field localizer 1222, HRTF memory 1225, and audio / visual content memory 1218 may be included in an auxiliary unit 1200C (which may correspond to the auxiliary unit 1100 described above). The auxiliary unit 1200C may include a battery 1227 to power its components and / or to power the head device apparatus 1200A and / or the handheld controller 1200B. Including such components in an auxiliary unit that can be mounted to the user's waist can limit the size and weight of the head device apparatus 1200A, which in turn can reduce fatigue on the user's head and neck.

[0027] Although Fig.12 Elements corresponding to the various components of the example wearable system 1200 are presented, but various other suitable arrangements of these components will become apparent to those skilled in the art. For example, Fig.12 Elements presented in association with the auxiliary unit 1200C may be associated with the head device 1200A or the handheld controller 1200B instead. In addition, some wearable systems may completely abandon the handheld controller 1200B or the auxiliary unit 1200C. Such changes and modifications should be understood to be included within the scope of the disclosed examples.

[0028] Audio Spatialization

[0029] The systems and methods described below can be implemented in an augmented reality or mixed reality system, such as described above. For example, one or more processors (e.g., CPU, DSP) of the augmented reality system can be used to process audio signals or implement the steps of the computer-implemented method described below; sensors (e.g., cameras, acoustic sensors, IMU, LIDAR, GPS) of the augmented reality system can be used to determine the position and / or orientation of a user of the system or elements in the user's environment; and speakers of the augmented reality system can be used to present audio signals to the user.

[0030] In an augmented reality or mixed reality system as described above, one or more processors (e.g., a DSP audio sound field localizer 1222) may process one or more audio signals for presentation to a user of a wearable head device via one or more speakers (e.g., the left speaker 1212 and the right speaker 1214 described above). In some embodiments, one or more speakers may belong to a unit separate from the wearable head device (e.g., a pair of headphones that communicate with the wearable head device). The processing of audio signals requires a compromise between the perceived realism of the audio signals—for example, the degree to which the audio signals presented to the user in a mixed reality environment match the user's expectations of how the audio signals will sound in a real environment—and the computational overhead involved in processing the audio signals. Realistically spatializing audio signals in a virtual environment may be critical to creating an immersive and believable user experience.

[0031] Figure 1A A spatialization system 100A (hereinafter "system 100A") is shown according to some embodiments. System 100A includes one or more encoders 104A-N, a mixer 106, and one or more speakers 108A-M. System 100A creates a soundscape (sound environment) by spatializing input sounds / signals corresponding to objects to be presented in the soundscape, and delivers the soundscape through one or more speakers 108A-M.

[0032] The system 100A receives one or more input signals 102A-N. The one or more input signals 102A-N may include digital audio signals corresponding to objects to be presented in the soundscape. In some embodiments, the digital audio signals may be pulse code modulated (PCM) waves of audio data. The total number of input signals (N) may represent the total number of objects to be presented in the soundscape.

[0033] Each of the one or more encoders 104A-N receives at least one of the one or more input signals 102A-N and outputs one or more gain-adjusted signals. For example, in some embodiments, encoder 104A receives input signal 102A and outputs a gain-adjusted signal. In some embodiments, each encoder outputs a gain-adjusted signal for each of one or more speakers 108A-M for delivering a soundscape. For example, encoder 104A outputs M gain-adjusted signals for each of speakers 108A-M. Speakers 108A-M may belong to, for example, an augmented reality or mixed reality system as described above; for example, one or more of speakers 108A-M may belong to a wearable head device as described above and may be configured to present audio signals directly to the ears of a user wearing the device. In order to make objects in the soundscape appear to originate from a specific location / proximity, each of the one or more encoders 104A-N sets the value of a control signal input to a gain module accordingly.

[0034] Each of the one or more encoders 104A-N includes one or more gain modules. For example, encoder 104A includes gain module g_A1-AM. In some embodiments, each of the one or more encoders 104A-N in system 100A may include the same number of gain modules. For example, each of the one or more encoders 104A-N may each include M gain modules. In some embodiments, the total number of gain modules in the encoder corresponds to the total number of speakers that transmit the soundscape. Each gain module receives at least one input signal of one or more input signals 102A-N, adjusts the gain of the input signal, and outputs a signal whose gain is adjusted. For example, gain module g_A1 receives input signal 102A, adjusts the gain of input signal 102A, and outputs a signal whose gain is adjusted. Each gain module adjusts the gain of the input signal based on the value of the control signal of one or more control signals CTRL_A1-NM. For example, gain module g_A1 adjusts the gain of input signal 102A based on the value of control signal CTRL_A1. Each encoder adjusts the value of the control signal input to the gain module based on the position / proximity of the object to be presented in the soundscape corresponding to the input signal. Each gain block may be a multiplier that multiplies the input signal by a factor that is a function of the value of the control signal.

[0035] The mixer 106 receives the gain-adjusted signals from the encoders 104A-N, mixes the gain-adjusted signals, and outputs the mixed signals to the speakers 108A-M. The speakers 108A-M receive the mixed signals from the mixer 106 and output the sounds. In some embodiments, the mixer 106 may be removed from the system 100A if there is only one input signal (e.g., input 102A).

[0036] In some embodiments, to perform this operation, a spatialization system ("spatializer") processes each input signal (e.g., a digital audio signal ("source")) using a pair of head-related transfer function (HRTF) filters that simulate the propagation and diffraction of sound through and by the user's outer ears and head. The pair of HRTF filters includes an HRTF filter for the user's left ear and an HRTF filter for the user's right ear. The outputs of the left ear HRTF filters for all sources are mixed together and played through the left ear speaker, and the outputs of the right ear HRTF filters for all sources are mixed together and played through the right ear speaker.

[0037] Figure 1B A spatialization system 100B (hereinafter "system 100B") is shown according to some embodiments. The system 100B creates a soundscape (sound environment) by spatializing input sounds / signals. Figure 1B The system 100B shown in FIG. 1 is similar to Figure 1A 10A, but may differ in some respects. For example, in example system 100A, the output of mixer 106 is input to speakers 108A-M. In system 100B, the output of mixer 106 is input to decoder 110, and the output of decoder 110 is input to left ear speaker 112A and right ear speaker 112B (hereinafter collectively referred to as "speakers 112"). In some embodiments, if there is only one input signal (e.g., input 102A), mixer 106 can be removed from system 100A.

[0038] In this example, the decoder 110 includes a left HRTF filter L_HRTF_1-M and a right HRTF filter R_HRTF_1-M. The decoder 110 receives a mixed signal from the mixer 106, filters and sums the mixed signal, and outputs the filtered signal to the speaker 112. For example, the decoder 110 receives a first mixed signal from the mixer 106, which represents a first object to be presented in the soundscape. Continuing with this example, the decoder 110 processes the first mixed signal through a first left HRTF filter L_HRTF_1 and a first right HRTF filter R_HRTF_1. Specifically, the first left HRTF filter L_HRTF_1 filters the first mixed signal and outputs a first left filtered signal, and the first right HRTF filter R_HRTF_1 filters the first mixed signal and outputs a first right filtered signal. The decoder 110 adds the first left filtered signal to other left filtered signals (e.g., the signal output from the left HRTF filter L_HRTF_2-M) and outputs the left output signal to the left ear speaker 112A. The decoder 110 adds the first right filtered signal to other right filtered signals (e.g., the signal output from the right HRTF filter R_HRTF_2-M) and outputs the right output signal to the right ear speaker 112B.

[0039] In some embodiments, the decoder 110 may include a group of HRTF filters. Each of the HRTF filters in the group can model a specific direction relative to the user's head. In some embodiments, a computationally efficient rendering method can be used, in which the incremental processing cost for each virtual sound source is minimized. These methods can be based on the decomposition of HRTF data on a fixed set of spatial functions and a fixed set of basis filters. In these embodiments, each mixed signal from the mixer 106 can be mixed into the input of the HRTF filter, which models the direction closest to the direction of the source. The level of the signal mixed into each of those HRTF filters is determined by the specific direction of the source.

[0040] If the direction and / or position of an object presented in the soundscape changes, encoders 104A-N may change the values ​​of control signals CTRL_A1-NM for gain modules g_A1-NM to appropriately present the object in the soundscape.

[0041] In some embodiments, encoders 104A-N may instantaneously change the values ​​of control signals CTRL_A1-NM for gain modules g_A1-NM. Figure 1A System 100A and / or Figure 1B In the system 100B of FIG. 1 , momentarily changing the value of the control signal CTRL_A1-NM may cause acoustic artifacts at the speakers 108A-M in the system 100A and / or at the speaker 112 in the system 100B. The acoustic artifact may be, for example, a "click" sound. The severity of the acoustic artifact caused by momentarily changing the value of the control signal may depend on a combination of the amount of gain change and the amplitude of the input signal at the time of the gain change.

[0042] To reduce such sound artifacts, in some embodiments, the encoders 104A-N may change the value of the control signal CTRL_A1-NM for the gain modules g_A1-NM over a period of time, rather than instantaneously. In some embodiments, the encoders 104A-N may calculate a new value for the control signal CTRL_A1-NM for each sample in the input signal 102A-N. The new value for the control signal CTRL_A1-NM may be only slightly different from the previous value. The new value may follow a linear curve, an exponential curve, etc. This process may be repeated until the desired mixing level for the new direction / position is reached. However, with respect to Figure 1A System 100A and / or Figure 1B For the system 100B, calculating new values ​​for the control signals CTRL_A1 -NM for every sample of the input signals 102A-N may be computationally expensive and time consuming.

[0043] In some embodiments, encoders 104A-N may repeatedly calculate new values ​​for control signals CTRL_A1-NM, for example, every few samples, every two samples, every four samples, every ten samples, etc. This process may be repeated until the desired mixing level for the new direction / position is reached. Figure 1A System 100A and / or Figure 1B Calculating new values ​​for control signals CTRL_A1-NM every few samples in system 100B may result in acoustic artifacts at speakers 108A-M in system 100A and / or speaker 112 in system 100B. The acoustic artifacts may be, for example, a "clipping" sound.

[0044] In order to reduce the sound artifacts, in some embodiments, the encoder can search for the input signal for zero crossing (zerocrossing), and adjust the value of the control signal at the time point of zero crossing. In some embodiments, the encoder may take many calculation cycles to search for the input signal for zero crossing, and adjust the value of the control signal at the time point of zero crossing. However, if the input signal has a direct current (DC) bias, the encoder may never detect or determine the zero crossing in the input signal, and therefore will never adjust the value of the control signal. Therefore, a high-pass filter or a DC blocking filter can be introduced before the encoder to reduce / remove the DC bias and ensure that there are enough zero crossings in the signal. In some embodiments of the system (e.g., system 100A and / or system 100B), a high-pass filter or a DC blocking filter can be introduced before each encoder in the system. Once the DC bias is reduced / removed from the input signal, the encoder can search the input signal without the DC bias for zero crossing, and adjust the value of the control signal at the time point of zero crossing. Searching for zero crossing may be time-consuming. If the system includes other components or modules that make changes to the signal, those other components or modules will similarly search the signal input to another component or module for zero crossings and adjust the values ​​of the parameters of the various components or modules at the time of the zero crossing.

[0045] As a non-limiting example, Figure 2A A system 200 is shown that includes an encoder 204, a mixer 206, and first to fourth speakers 208A-D. The example system 200 is similar to the system 100A, but may differ in some aspects. The system 200 creates a soundscape (sound environment) by spatializing input sounds / signals corresponding to objects to be presented in the soundscape, and delivers the soundscape through the first to fourth speakers 208A-D.

[0046] The system 200 receives an input signal 202. The input signal 202 may include a digital audio signal corresponding to an object to be presented in a soundscape. An encoder 204 receives the input signal 202 and outputs four gain-adjusted signals. The encoder 204 outputs a gain-adjusted signal for each of the first to fourth speakers 208A-D that deliver the soundscape. In order to make the objects in the soundscape appear to originate from a specific location / proximity, the encoder 204 sets the value of the control signal input to the first to fourth gain modules g_1-4 accordingly. The encoder 204 includes the first to fourth gain modules g_1-4. The total number of gain modules corresponds to the total number of speakers that deliver the soundscape. Each of the first to fourth gain modules g_1-4 receives the input signal 202, adjusts the gain of the input signal 202, and outputs the gain-adjusted signal. Each of the first to fourth gain modules g_1-4 adjusts the gain of the input signal 202 based on the value of the control signal of the first to fourth control signals CTRL_1-4. For example, the first gain module g_1 adjusts the gain of the input signal 202 based on the value of the first control signal CTRL_1. The encoder 204 adjusts the values ​​of the first to fourth control signals CTRL_1-4 input to the first to fourth gain modules g_1-4 based on the position and / or proximity of the object to be presented in the soundscape corresponding to the input signal 202. The mixer 206 receives the gain-adjusted signal from the encoder 204, mixes the gain-adjusted signal, and outputs the mixed signal to the first to fourth speakers 208A-D. In this example, because there is only one input signal 202 and only one encoder 204, the mixer 206 does not mix any gain-adjusted signal. The first to fourth speakers 208A-D receive the mixed signal from the mixer 106 and output sound.

[0047] Figure 2B An environment 240 is shown including first through fourth speakers 208A-D and a user 220. The speakers 208A-D may belong to an augmented reality system (e.g., including a wearable head device), and the user 220 may be a user of the augmented reality system. Figure 2C A virtual bee 222-1 is shown at a first position / proximity in an environment 240. The virtual bee 222-1 is an object to be presented in a soundscape delivered by the first through fourth speakers 208A-D. The virtual bee 222-1 may be visually presented in a display of an augmented reality system used by a user 220; it is generally desirable that the soundscape be consistent with the visual display of the virtual bee 222-1. The encoder 204 receives an input signal 202 including a digital audio signal corresponding to the virtual bee 222-1. The encoder 204 sets the values ​​of the first through fourth control signals CTRL_1-4 based on the first position / proximity of the virtual bee 222-1. Figure 2D Shown based on Figure 2C 1 to 4 control signals CTRL_1-4 of the first position / proximity of the virtual bee 222-1 as depicted in FIG. Figure 2D As shown, based on the first position / proximity of the virtual bee 222-1 relative to the user 220, the first and second control signals CTRL_1-2 have the same non-zero value (e.g., 0.5), and the third and fourth control signals CTRL_3-4 have zero values. That is, since the virtual bee 222-1 will be presented as being located directly in front of the user 220 in the soundscape, the first and second control signals CTRL_1-2 have the same non-zero value, and the third and fourth control signals CTRL_3-4 have zero values.

[0048] Figure 2E A virtual bee 222-1 is shown at a second position / proximity in the environment. The encoder 204 adjusts the values ​​of the first to fourth control signals CTRL_1-4 based on the second position / proximity of the virtual bee 222-2. For example, the encoder 204 increases the value of the first control signal CTRL_1 relative to the value of the first control signal CTRL_1 when the virtual bee 222-1 is at the first position / proximity (e.g., a value of 0.75), the encoder 204 decreases the value of the second control signal CTRL_2 relative to the value of the second control signal CTRL_2 when the virtual bee 222-1 is at the first position / proximity (e.g., a value of 0.25), and the encoder 204 does not make any adjustments to the third to fourth control signals CTRL_3-4, which remain at zero values.

[0049] Figure 2F According to some embodiments, Figure 2E 2 and 3. The values ​​of the first to fourth control signals CTRL_1-4 of the second position / proximity of the virtual bee 222-2 are depicted in FIG. Figure 2F As shown, encoder 204 instantaneously changes the values ​​of first and second control signals CTRL_1-2 at time t_1. As described above, instantaneously changing the values ​​of first and second control signals CTRL_1-2 at time t_1 may result in undesirable sound artifacts at speakers 208A-D. The sound artifacts may be, for example, a "click" sound.

[0050] Figure 2G According to some embodiments, Figure 2E 2 and 3. The values ​​of the first to fourth control signals CTRL_1-4 of the second position / proximity of the virtual bee 222-2 are depicted in FIG. Figure 2GAs shown, the encoder 204 changes the values ​​of the first and second control signals CTRL_1-2 over a period of time. In this embodiment, the encoder 204 may calculate new values ​​for the first and second control signals CTRL_1-2 for each sample of the input signal 202. The new values ​​for the first and second control signals CTRL_1-2 may be only slightly different from the previous values. The process can be repeated until the desired mixing level for the new direction / position is reached. For example, the process can be repeated until the value of the first control signal CTRL_1 increases (e.g., from 0.5 to 0.75) and the value of the second control signal CTRL_2 decreases (e.g., from 0.5 to 0.25). However, as described above, calculating new values ​​for the first and second control signals CTRL_1-2 for each sample of the input signal 202 may be computationally expensive and time consuming.

[0051] Figure 2H According to some embodiments, Figure 2E 2 and 3. The values ​​of the first to fourth control signals CTRL_1-4 of the second position / proximity of the virtual bee 222-2 are depicted in FIG. Figure 2H As shown, the encoder 204 changes the values ​​of the first and second control signals CTRL_1-2 over a period of time. In this embodiment, the encoder 204 can calculate new values ​​for the first and second control signals CTRL_1-2 every few samples. This process can be repeated until the desired mixing level for the new direction / position is reached. However, as described above, once the new values ​​for the first and second control signals CTRL_1-2 are calculated every few samples, undesirable sound artifacts may result at the speakers 208A-D. The sound artifact may be, for example, a "clipped" sound.

[0052] Figure 3A A spatialization system 300 (hereinafter referred to as "system 300") according to some embodiments is shown. The example system 300 creates a soundscape (sound environment) by spatializing input sounds / signals. The system 300 shown in FIG. 3 is similar to Figure 1A, but may be different in some aspects. In addition to one or more encoders 304A-N, mixer 306, and one or more speakers 308A-M, system 300 includes one or more pre-emphasis filters 332A-N and one or more de-emphasis filters 334A-M. Adding one or more pre-emphasis filters 332A-N and one or more de-emphasis filters 334A-M allows one or more encoders 304A-N to instantaneously change the value of control signal CTRL_A1-NM while minimizing the sound artifacts at the speaker 308A-M. In some embodiments, one or more pre-emphasis filters 332A-N and one or more de-emphasis filters 334A-N reduce noise. One or more pre-emphasis filters 332A-N and one or more de-emphasis filters 334A-N can be complementary filters. One or more pre-emphasis filters 332A-N and one or more de-emphasis filters 334A-N can cancel each other, except at low frequencies where DC is blocked in some cases.

[0053] In this example, each of the one or more pre-emphasis filters 332A-N receives at least one of the one or more input signals 302A-N, filters the input signal, and outputs the filtered signal to an encoder in the one or more encoders 304A-N. Each pre-emphasis filter filters at least one input signal, for example, by reducing low frequency energy from the input signal. The amplitude of the filtered signal output from the pre-emphasis filter can be closer to zero than the amplitude of the input signal. The severity of the sound artifacts that may be caused by instantaneously changing the value of the control signal can be reduced by the amplitude of the filtered signal being close to zero, where the severity can depend on a combination of the gain change amount and the amplitude of the input signal at the time of the gain change.

[0054] In an example, each of the one or more encoders 304A-N may adjust the value of a control signal input to a gain module based on the location / proximity of an object to be presented in the soundscape, where the object corresponds to the input signal and thus the filtered signal. Each encoder may adjust the value of the control signal instantaneously without causing audible artifacts at the speakers 308A-M. This is because each gain module adjusts the gain of the filtered signal (e.g., the output of the pre-emphasis filter 332A-N) without directly adjusting the input signal.

[0055] In an example, each of the one or more de-emphasis filters 334A-N receives a signal (e.g., one or a mixed signal in the mixed signal output from the mixer 306), reconstructs a signal based on the mixed signal, and outputs the reconstructed signal to a speaker in the one or more speakers 308A-M. Each de-emphasis filter can filter the signal, for example, by reducing high frequency energy from the signal. In some embodiments, the de-emphasis filter can convert all sudden changes in the amplitude of the input signal into changes in the slope of the waveform.

[0056] Changing the value of the control signal momentarily may cause a change in the amplitude of the waveform of the signal, which may introduce dominant high frequency noise. The pre-emphasis filter reduces the amplitude of at least one input signal. The de-emphasis filter converts a sudden change in the amplitude of the signal into a change in the slope of the waveform with reduced high frequency noise.

[0057] Figure 3B An example pre-emphasis filter according to some embodiments is shown. The pre-emphasis filter receives a received signal, filters the received signal, and outputs a transmitted signal. The transmitted signal is a filtered version of the received signal. The pre-emphasis filter may reduce or attenuate the amplitude of the low-frequency content of the received signal while maintaining or amplifying the amplitude of the high-frequency content of the received signal. In some embodiments, the pre-emphasis filter brings the amplitude of the received signal closer to zero. The pre-emphasis filter may help to attenuate any DC offset that may be present in the received signal. In some embodiments, the pre-emphasis filter may include a high-pass filter, such as a first-order high-pass filter. In some embodiments, the pre-emphasis filter may include a first derivative filter. The first derivative filter may have a roll-off of approximately six decibels per octave at a reduced frequency (e.g., from Nyquist to DC). Therefore, at low frequencies, the received signal may be greatly attenuated relative to an unfiltered version of the received signal.

[0058] Figure 3C An example de-emphasis filter according to some embodiments is shown. The de-emphasis filter receives a received signal, filters the received signal, and outputs a transmitted signal. It should be noted that Figure 3C The received signal and the transmitted signal are not necessarily the same Figure 3BThe received signal is the same as the transmitted signal. The transmitted signal is a filtered version of the received signal. The de-emphasis filter can reduce or attenuate the amplitude of the high-frequency content of the received signal while maintaining or amplifying the amplitude of the low-frequency content of the received signal. In some embodiments, the de-emphasis filter may include a low-pass filter. In some embodiments, the de-emphasis filter may include an integral filter, such as a leaky integral. The leaky integral may have a boost of about six decibels per octave in the case of a reduced frequency. Therefore, at low frequencies, the received signal may be greatly amplified relative to an unfiltered version of the received signal. In some embodiments, the de-emphasis filter may include a DC blocking filter.

[0059] like Figure 3A As shown, de-emphasis filters 334A-M may be located between mixer 306 and one or more speakers 308A-M. In this embodiment, the number of de-emphasis filters 334A-M may be the same as the number of outputs of mixer 306, and the number of outputs of mixer 306 may be the same as the number of one or more speakers 308A-M.

[0060] Figure 4 A spatialization system 400 (hereinafter "system 400") is shown in accordance with some embodiments. System 400 creates a soundscape (sound environment) by spatializing input sounds / signals. Figure 4 The system 400 shown in FIG. Figure 3A 4. The system 300 shown in FIG. 4 is similar to the system 300 shown in FIG. 4, but may differ in some aspects. In the system 400, one or more de-emphasis filters 434A1-NM may be located between the one or more encoders 404A-N and the mixer 406. In this embodiment, the number of de-emphasis filters 434A1-NM may be the same as the number of outputs from the one or more encoders 404A-N.

[0061] Figure 5 A spatialization system 500 (hereinafter "system 500") is shown in accordance with some embodiments. System 500 creates a soundscape (sound environment) by spatializing input sounds / signals. Figure 5 The system 500 shown in FIG. 1 is similar to Figure 1B, but may differ in some respects. In addition to one or more encoders 504A-N, mixer 506, decoder 510, left ear speaker 512A, and right ear speaker 512B, system 500 includes one or more pre-emphasis filters 532A-N, left de-emphasis filter 534A, and right de-emphasis filter 534B. Adding one or more pre-emphasis filters 532A-N and left and right de-emphasis filters 534A-B can enable one or more encoders 504A-N to instantaneously change the value of control signal CTRL_A1-NM without causing sound artifacts at the left and right speakers 512A-B. In some embodiments, one or more pre-emphasis filters 532A-N and left and right de-emphasis filters 534A-B reduce noise. One or more pre-emphasis filters 532A-N can be used with Figure 3B The left and right de-emphasis filters 534A-B may be the same as the pre-emphasis filters shown in and described above. Figure 3C The de-emphasis filter shown in is the same as described above.

[0062] Figure 6 A spatialization system 600 (hereinafter "system 600") is shown in accordance with some embodiments. System 600 creates a soundscape (sound environment) by spatializing input sounds / signals. Figure 6 The system 600 shown in FIG. 1 is similar to Figure 5 6, but may differ in some aspects. In system 600, one or more de-emphasis filters 634A-M may be located between mixer 606 and decoder 610. In this embodiment, the number of de-emphasis filters 634A-M may be the same as the number of outputs of mixer 606, which may be the same as the number of left and right HRTF filter pairs in decoder 610.

[0063] Figure 7 A spatialization system 700 (hereinafter "system 700") is shown in accordance with some embodiments. System 700 creates a soundscape (sound environment) by spatializing input sounds / signals. Figure 7 The system 700 shown in FIG. 1 is similar to Figure 5 , but may differ in some aspects. In system 700, one or more de-emphasis filters 734A1-NM may be located between one or more encoders 704A-N and mixer 706. In this embodiment, the number of de-emphasis filters 734A1-NM may be the same as the number of outputs from one or more encoders 704A-N.

[0064] Figure 8A spatialization system 800 (hereinafter referred to as "system 800") according to some embodiments is shown. System 800 includes a pre-emphasis filter 802, a pre-processing module 804, a clustered reflection module 814, a reverberation module 816, a reverberation pan module 818, a reverberation occlusion module 820, a multi-channel decorrelation filter bank 822, a virtualizer 824, and a de-emphasis filter 826.

[0065] In some embodiments, the filter 806, the clustered reflections 814, the reverberation module 816, the reverberation panning module 818, and / or the reverberation masking module 820 can be adjusted based on one or more values ​​of one or more control signals. In embodiments without the pre-emphasis filter 802 and the de-emphasis filter 826, transiently and / or repeatedly changing the values ​​of the control signals can cause sound artifacts. The pre-emphasis filter 802 and the de-emphasis filter 826 can reduce the severity of the sound artifacts, such as described above.

[0066] In the example shown, the pre-emphasis filter 802 receives a 3D source signal, filters the 3D source signal, and outputs the filtered signal to the pre-processing module 804. The 3D source signal may be similar to that described above, for example, with respect to Figure 1A-1B , 3A and 4-7. The pre-emphasis filter 802 may be similar to the above, for example, Figure 3A-3B and the pre-emphasis filter described in 4-7.

[0067] The pre-processing module 804 includes one or more filters 806 , one or more pre-delay modules 808 , one or more translation modules 810 , and a switch 812 .

[0068] The filtered signal received from the pre-emphasis filter 802 is input to one or more filters 806. The one or more filters 806 can be, for example, a distance filter, an air absorption filter, a source directivity filter, an occlusion filter, an obstruction filter, etc. A first filter of the one or more filters 806 outputs a signal to the switch 812, and the remaining filters of the one or more filters 806 output corresponding signals to the pre-delay module 808.

[0069] Switch 812 receives the signal output from the first filter and directs the signal to the first panning module, the second panning module, or the interaural time difference (ITD) delay module. The ITD delay module outputs the first delayed signal to the third panning module and the second delayed signal to the fourth panning module.

[0070] One or more pre-delay modules 808 each receive a corresponding signal, delay the received signal, and output a delayed version of the received signal. The first pre-delay module outputs the first delayed signal to the fifth panning module. The remaining delay modules output the delayed signals to various reverb send buses.

[0071] One or more shift modules 810 each shift a corresponding input signal to a bus. The first shift module shifts the signal to a diffuse bus, the second shift module shifts the signal to a standard bus, the third shift module shifts the signal to a left bus, the fourth shift module shifts the signal to a right bus, and the fifth shift module shifts the signal to a clustered reflection bus.

[0072] The clustered reflection bus outputs a signal to the clustered reflection module 814. The clustered reflection module 814 generates clusters of reflections and outputs the clusters of reflections to the clustered reflection occlusion module.

[0073] The various reverb send buses output signals to the various reverb modules 816. The reverb modules 816 generate reverb and output the reverb to the various reverb panning modules 810. The reverb panning modules 818 pan the reverb to the various reverb masking modules 820. The reverb masking modules 820 model masking and other characteristics similar to the filters 806 and output the masked, panned reverb to the standard buses.

[0074] The multi-channel decorrelation filter bank 822 receives the diffuse bus and applies one or more decorrelation filters; for example, the filter bank 822 spreads the signal to create a non-point source sound and outputs the diffused signal to a standard bus.

[0075] Virtualizer 824 receives the left bus, the right bus, and the standard bus and outputs the signal to de-emphasis filter 826. Virtualizer 824 may be similar to the above, for example, Figure 1B and Figure 5-7 The de-emphasis filter 826 may be similar to that described above, for example, with respect to Figure 3A , 3C and the de-emphasis filter described in 4-7.

[0076] Various exemplary embodiments of the present disclosure are described herein. Reference is made to these examples in a non-limiting sense. These examples are provided to illustrate the wider application aspects of the present disclosure. Various changes and replacement equivalents may be made to the described disclosure without departing from the spirit and scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation, material, composition of matter, process, one or more process actions or one or more steps to one or more purposes, spirit or scope of the present disclosure. In addition, as will be appreciated by those skilled in the art, each of the various variations described and illustrated herein has separate components and features that may be easily separated or combined with any of the features in the other several embodiments without departing from the scope or spirit of the present disclosure. All of these modifications are intended to be within the scope of the claims associated with the present disclosure.

[0077] The present disclosure includes methods that can be performed using subject devices. The methods can include an act of providing such suitable devices. Such providing can be performed by an end user. In other words, the act of "providing" simply requires the end user to obtain, access, access, locate, set, activate, turn on or otherwise provide the necessary devices in the method. The methods described herein can be performed in any order of the events described that is logically possible and in the order of events described.

[0078] Exemplary aspects of the present disclosure and details about material selection and manufacturing have been described above. For other details of the present disclosure, these can be understood in conjunction with the above-referenced patents and publications and what is generally known or understood by those skilled in the art. The same can be established with respect to additional actions that are generally or logically utilized in accordance with aspects of the basic methods of the present disclosure.

[0079] In addition, although the present disclosure has been described with reference to several examples that optionally incorporate various features, the present disclosure is not limited to the disclosure described or indicated for each variation of the present disclosure. Various changes may be made to the described disclosure, and equivalents (whether or not included herein for the sake of brevity) may be substituted without departing from the actual spirit and scope of the present disclosure. In addition, where a range of values ​​is provided, it is understood that each intermediate value between the upper and lower limits of the range and any other stated or intermediate values ​​within the stated range are included in the present disclosure.

[0080] In addition, it is contemplated that any optional features of the described variations may be stated and claimed independently or in combination with any one or more of the features described herein. Reference to a singular item includes the possibility that the same item is present in the plurality. More specifically, as used herein and in the associated claims, the singular forms "one," "an," "said," and "the" include plural objects unless expressly stated otherwise. In other words, in the above description and in the claims associated with the present disclosure, the use of the article "at least one" target item is permitted. It should be further noted that such claims may be drafted to exclude any optional elements. Therefore, in conjunction with claim elements or using a "negative" limitation, this statement is intended to serve as an antecedent basis for the use of exclusive terms such as "solely," "only," and the like.

[0081] Without using such exclusive terms, the term "comprising" in the claims associated with the present disclosure shall allow for the inclusion of any additional elements, regardless of whether a given number of elements are recited in such claim or the addition of features may be considered to alter the nature of the elements described in the claim. Except as specifically defined herein, all technical and scientific terms used herein shall be given as broad a commonly understood meaning as possible while maintaining claim validity.

[0082] The breadth of the present disclosure is not limited to the embodiments and / or subject specification provided, but is limited only by the scope of the claim language associated with the present disclosure.

Claims

1. A method of presenting an audio signal to a user of a wearable head device, the method comprising: receiving a first input audio signal associated with a virtual environment presented on a display of the wearable head device; Processing the first input audio signal to generate a first output audio signal, the first output audio signal being associated with the virtual environment, wherein processing the first input audio signal comprises: applying one or more of a pre-emphasis filter and a de-emphasis filter to the first input audio signal; adjusting the gain of the first input audio signal; and presenting the first output audio signal via one or more speakers associated with the wearable head device, in: Applying the pre-emphasis filter to the first input audio signal comprises: attenuating a first frequency component of the first input audio signal, Applying the de-emphasis filter to the first input audio signal includes attenuating a second frequency component of the first input audio signal, the second frequency being higher than the first frequency, and One or more of the first frequency component and the second frequency component are associated with an acoustic artifact caused by a change in a control signal associated with the virtual environment.

2. The method of claim 1 , further comprising receiving a second input audio signal, in: Processing the first input audio signal to generate the first output audio signal further comprises mixing the first input audio signal with the second input audio signal via a mixer.

3. The method according to claim 1, wherein: Presenting the first output audio signal via one or more speakers of the wearable head device includes: applying a first head-related transfer function (HRTF) to the first output audio signal; presenting an output of the first HRTF to a left speaker of the one or more speakers of the wearable head device; applying a second HRTF to the first output audio signal; and An output of the second HRTF is presented to a right speaker of the one or more speakers of the wearable head device.

4. The method according to claim 1, wherein: Processing the first input audio signal to generate the first output audio signal further comprises: applying the output of the pre-emphasis filter to the input of one or more filters; shifting the first output of the one or more filters to generate a first shifted signal, a second shifted signal, a third shifted signal, and a fourth shifted signal; applying the first panned signal to a left bus; applying the second shifted signal to a right bus; applying the third shifted signal to a standard bus; applying the fourth shifted signal to a diffusion bus; applying the left bus, the right bus, the standard bus, and the diffusion bus as input to a virtualizer; and The de-emphasis filter is applied to the output of the virtualizer.

5. The method according to claim 4, wherein: Processing the first input audio signal to generate the first output audio signal further includes applying second outputs of the one or more filters as input to a clustered reflection module and applying an output of the clustered reflection module to the standard bus.

6. The method according to claim 4, wherein: Processing the first input audio signal to generate the first output audio signal further includes applying a second output of the one or more filters as an input to a reverberation module and applying an output of the reverberation module to the standard bus.

7. The method according to claim 4, wherein: The one or more filters include one or more of a distance filter, an air absorption filter, a source directivity filter, an occlusion filter, and a blocking filter.

8. A system comprising: A wearable head device including a display; one or more speakers; as well as One or more processors configured to perform a method comprising: receiving a first input audio signal associated with a virtual environment presented on the display of the wearable head device; Processing the first input audio signal to generate a first output audio signal, the first output audio signal being associated with the virtual environment, wherein processing the first input audio signal comprises: applying one or more of a pre-emphasis filter and a de-emphasis filter to the first input audio signal; and adjusting the gain of the first input audio signal; and The first output audio signal is presented via the one or more speakers, wherein: Applying the pre-emphasis filter to the first input audio signal comprises: attenuating a first frequency component of the first input audio signal, Applying the de-emphasis filter to the first input audio signal includes attenuating a second frequency component of the first input audio signal, the second frequency being higher than the first frequency, and One or more of the first frequency component and the second frequency component are associated with an acoustic artifact caused by a change in a control signal associated with the virtual environment.

9. The system of claim 8, wherein: The method further includes receiving a second input audio signal; as well as Processing the first input audio signal to generate the first output audio signal further comprises mixing the first input audio signal with the second input audio signal via a mixer.

10. The system according to claim 8, wherein: Presenting the first output audio signal via the one or more speakers comprises: applying a first HRTF to the first output audio signal; presenting an output of the first HRTF to a left speaker of the one or more speakers; applying a second HRTF to the first output audio signal; and An output of the second HRTF is presented to a right speaker of the one or more speakers.

11. The system according to claim 8, wherein: Processing the first input audio signal to generate the first output audio signal further comprises: applying the output of the pre-emphasis filter to the input of one or more filters; shifting the first output of the one or more filters to generate a first shifted signal, a second shifted signal, a third shifted signal, and a fourth shifted signal; applying the first panned signal to a left bus; applying the second shifted signal to a right bus; applying the third shifted signal to a standard bus; applying the fourth shifted signal to a diffusion bus; applying the left bus, the right bus, the standard bus, and the diffusion bus as input to a virtualizer; and The de-emphasis filter is applied to the output of the virtualizer.

12. The system according to claim 11, wherein: Processing the first input audio signal to generate the first output audio signal further includes applying second outputs of the one or more filters as input to a clustered reflection module and applying an output of the clustered reflection module to the standard bus.

13. The system according to claim 11, wherein: Processing the first input audio signal to generate the first output audio signal further includes applying a second output of the one or more filters as an input to a reverberation module and applying an output of the reverberation module to the standard bus.

14. The system according to claim 11, wherein: The one or more filters include one or more of a distance filter, an air absorption filter, a source directivity filter, an occlusion filter, and a blocking filter.

15. A non-transitory computer readable medium storing instructions that, when executed by one or more processors, cause the one or more processors to perform a method of presenting an audio signal to a user of a wearable head device, the method comprising: receiving a first input audio signal associated with a virtual environment presented on a display of the wearable head device; Processing the first input audio signal to generate a first output audio signal, the first output audio signal being associated with the virtual environment, wherein processing the first input audio signal comprises: applying one or more of a pre-emphasis filter and a de-emphasis filter to the first input audio signal; adjusting the gain of the first input audio signal; and presenting the first output audio signal via one or more speakers associated with the wearable head device, in: Applying the pre-emphasis filter to the first input audio signal comprises: attenuating a first frequency component of the first input audio signal, Applying the de-emphasis filter to the first input audio signal includes attenuating a second frequency component of the first input audio signal, the second frequency being higher than the first frequency, and One or more of the first frequency component and the second frequency component are associated with an acoustic artifact caused by a change in a control signal associated with the virtual environment.

16. The non-transitory computer readable medium of claim 15, wherein: The method further includes receiving a second input audio signal; as well as Processing the first input audio signal to generate the first output audio signal further comprises mixing the first input audio signal with the second input audio signal via a mixer.

17. The non-transitory computer readable medium of claim 15, wherein: Presenting the first output audio signal via one or more speakers of the wearable head device includes: applying a first HRTF to the first output audio signal; presenting an output of the first HRTF to a left speaker of the one or more speakers of the wearable head device; applying a second HRTF to the first output audio signal; and An output of the second HRTF is presented to a right speaker of the one or more speakers of the wearable head device.

18. The non-transitory computer readable medium of claim 15, wherein: Processing the first input audio signal to generate the first output audio signal further comprises: applying the output of the pre-emphasis filter to the input of one or more filters; shifting the first output of the one or more filters to generate a first shifted signal, a second shifted signal, a third shifted signal, and a fourth shifted signal; applying the first panned signal to a left bus; applying the second shifted signal to a right bus; applying the third shifted signal to a standard bus; applying the fourth shifted signal to a diffusion bus; applying the left bus, the right bus, the standard bus, and the diffusion bus as input to a virtualizer; and The de-emphasis filter is applied to the output of the virtualizer.

19. The non-transitory computer readable medium of claim 18, wherein: Processing the first input audio signal to generate the first output audio signal further includes applying a second output of the one or more filters as an input to a reverberation module and applying an output of the reverberation module to the standard bus.

20. The non-transitory computer readable medium of claim 18, wherein: The one or more filters include one or more of a distance filter, an air absorption filter, a source directivity filter, an occlusion filter, and a blocking filter.

21. A method of presenting an audio signal to a user of a wearable head device, the method comprising: receiving a first input audio signal associated with a virtual environment presented on a display of the wearable head device; as well as Processing the first input audio signal to generate an output audio signal, the output audio signal being associated with the virtual environment, wherein processing the first input audio signal comprises: applying a pre-emphasis filter to the first input audio signal to attenuate low frequency components of the first input audio signal and generate a filtered first input audio signal, wherein: The attenuated low frequency components are associated with a reduction in acoustic artifacts, and The sound artifacts are caused by changes in control signals associated with movement of virtual objects in the virtual environment.

22. The method according to claim 21, wherein: Processing the first input audio signal includes applying a gain to the first input audio signal, wherein the gain is associated with a position in the virtual environment.

23. The method according to claim 22, wherein: The gain includes a first gain and a second gain, wherein the first gain is also associated with a first position of the virtual environment, and the method further includes: applying the second gain to the first input audio signal, wherein the second gain is associated with a second position in the virtual environment.

24. The method according to claim 21, wherein: The level of the output audio signal is based on the location of the sound in the virtual environment.

25. The method according to claim 21, wherein: The pre-emphasis filter includes a first derivative filter.

26. The method of claim 21, further comprising: receiving a second input audio signal; as well as Processing the second input audio signal includes applying a second pre-emphasis filter to the second input audio signal to attenuate low frequency components of the second input audio signal and generate a filtered second input audio signal.

27. The method according to claim 26, further comprising: The filtered first input audio signal is mixed with the filtered second input audio signal via a mixer.

28. The method of claim 21, wherein: Processing the first input audio signal comprises applying a first gain and a second gain to the first input audio signal, wherein: The first gain and the second gain are associated with movement of the virtual object in the virtual environment, and The control signal change includes changing from the first gain to the second gain.

29. The method according to claim 21, wherein: Processing the first input audio signal further includes applying a de-emphasis filter to the first input audio signal.

30. The method of claim 29, wherein: Applying the de-emphasis filter to the first input audio signal includes attenuating high frequency components of the first input audio signal.

31. A wearable device comprising: monitor; one or more speakers; as well as One or more processors configured to perform a method comprising: receiving a first input audio signal associated with a virtual environment presented on the display; and Processing the first input audio signal to generate an output audio signal, the output audio signal being associated with the virtual environment, wherein processing the first input audio signal comprises: applying a pre-emphasis filter to the first input audio signal to attenuate low frequency components of the first input audio signal and generate a filtered first input audio signal, wherein: The attenuated low frequency components are associated with a reduction in acoustic artifacts caused by changes in control signals associated with movement of virtual objects in the virtual environment.

32. The wearable device according to claim 31, wherein: Processing the first input audio signal includes applying a gain to the first input audio signal, wherein the gain is associated with a position in the virtual environment.

33. The wearable device according to claim 32, wherein: The gain includes a first gain and a second gain, the first gain is also associated with a first position of the virtual environment, and the method further includes: applying the second gain to the first input audio signal, wherein the second gain is associated with a second position in the virtual environment.

34. The wearable device of claim 31, wherein: The level of the output audio signal is based on the location of the sound in the virtual environment.

35. The wearable device of claim 31, wherein: The method further comprises: receiving a second input audio signal; and Processing the second input audio signal includes applying a second pre-emphasis filter to the second input audio signal to attenuate low frequency components of the second input audio signal and generate a filtered second input audio signal.

36. The wearable device of claim 35, wherein: The method further includes mixing the filtered first input audio signal with the filtered second input audio signal via a mixer.

37. The wearable device of claim 31, wherein: Processing the first input audio signal comprises applying a first gain and a second gain to the first input audio signal, wherein: The first gain and the second gain are associated with movement of the virtual object in the virtual environment, and The control signal change includes changing from the first gain to the second gain.

38. The wearable device of claim 31, wherein: Processing the first input audio signal further includes applying a de-emphasis filter to the first input audio signal.

39. The wearable device of claim 38, wherein: Applying the de-emphasis filter to the first input audio signal includes attenuating high frequency components of the first input audio signal.

40. A non-transitory computer-readable storage medium storing one or more programs, the one or more programs comprising instructions that, when executed by an electronic device having one or more processors and a memory, cause the device to perform a method comprising: receiving a first input audio signal associated with a virtual environment presented on a display of the electronic device; as well as Processing the first input audio signal to generate an output audio signal, the output audio signal being associated with the virtual environment, wherein processing the first input audio signal comprises: applying a pre-emphasis filter to the first input audio signal to attenuate low frequency components of the first input audio signal and generate a filtered first input audio signal, wherein: The attenuated low frequency components are associated with a reduction in acoustic artifacts, and The sound artifacts are caused by changes in control signals associated with movement of virtual objects in the virtual environment.

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