Patent Publication Number: US-2022232341-A1

Title: Spatialized audio relative to a peripheral device

Description:
PRIORITY CLAIM 
     This application is a continuation of U.S. patent application Ser. No. 16/904,087, filed Jun. 17, 2020, where the entire contents of the application are hereby incorporated by reference. 
    
    
     BACKGROUND 
     Aspects and implementations of the present disclosure are generally directed to audio systems, for example, audio systems which include a peripheral device and a wearable audio device. 
     Audio systems, for example, augmented reality audio systems, may utilize a technique referred to as sound externalization to render audio signals to a listener to trick their mind into believing they are perceiving sound from physical locations within an environment. Specifically, when listening to audio, particularly audio through stereo headphones, many listeners perceive the sound as coming from “inside their head”. Sound externalization refers to the process of simulating and rendering sounds such that they are perceived by the user as though they are coming from the surrounding environment, i.e. the sounds are “external” to the listener. 
     As these augmented reality audio systems are capable of being executed using mobile devices, simulating or externalizing sound sources at predetermined positions may not be desirable to some users. 
     SUMMARY OF THE DISCLOSURE 
     The present disclosure relates to audio systems, methods, and computer program products which include a wearable audio device and a peripheral device. The wearable audio device and the peripheral device are capable of determining their respective positions and/or orientations within an environment as well as their respective positions and/or orientations with respect to each other. Once the relative positions and orientations between, e.g., the wearable audio device and the peripheral device are known, virtual sound sources may be generated at fixed positions and orientations relative to the peripheral device such that any change in position and/or orientation of the peripheral device produces a proportional change in the position and/or orientation of the virtual sound sources. Additionally, one or more orders of reflected audio paths may be simulated for each virtual sound source to increase the sense of realism of the simulated sources. For instance, each sound path, e.g., direct sound paths, as well as the first order and second order reflected sound paths, can be produced by modifying the original audio signal using a plurality of left head-related transfer functions (HRTFs) and a plurality of right HRTFs to simulate audio as though it were perceived by the user&#39;s left and right ears, respectively, coming from each virtual sound source. 
     Thus, the disclosure includes audio systems, methods, and computer program products to produce spatialized and externalized audio that is “pinned” to the peripheral device. The systems, methods, and computer program products can utilize: 1) a means of tracking the user&#39;s head location and/or orientation; 2) means of tracking the location and/or orientation of the peripheral device; and, 3) a means of rendering spatialized audio signals where the locations of the virtual sound sources are anchored or pinned in some way to the peripheral device. This could include placing virtual sound sources to the virtual left and virtual right of the peripheral device for left and right channel audio signals. It can also include a discrete, extracted, or phantom center virtual sound source for center channel audio. The concepts disclosed herein also scale to additional channels, e.g., could include additional channels for implementation of virtual surround sound systems (e.g., virtual 5.1 or 7.1). The concepts can also include object-oriented rendering like, for example, the object-oriented rendering provided by Dolby Atmos systems, which can add virtual height channels to the virtual surround sound system (e.g., virtual 5.1.2 or 5.1.4). 
     In one example, a computer program product for simulating audio signals is provided, the computer program product including a set of non-transitory computer-readable instructions stored in a memory, the set of non-transitory computer-readable instructions being executable on a processor and are configured to: obtain or receive an orientation of a wearable audio device relative to a peripheral device within an environment; generate a first modified audio signal, wherein the first modified audio signal is modified using a first head-related transfer function (HRTF) based at least in part on the orientation of the wearable audio device relative to the peripheral device; generate a second modified audio signal, wherein the second modified audio signal is modified using a second head-related transfer function (HRTF) based at least in part on the orientation of the wearable audio device relative to the peripheral device; send the first modified audio signal and the second modified audio signal to the wearable audio device, wherein the first modified audio signal is configured to be rendered using a first speaker of the wearable audio device and the second modified audio signal is configured to be rendered using a second speaker of the wearable audio device. 
     In one aspect, the set of non-transitory computer readable instructions are further configured to: obtain or receive a position of the wearable audio device relative to a position of the peripheral device within the environment and wherein modifying the first modified audio signal and modifying the second modified audio signal include attenuation based at least in part on a calculated distance between the position of the wearable audio device and the position of the peripheral device. 
     In one aspect, the set of non-transitory computer readable instructions are further configured to: obtain or receive an orientation of the peripheral device relative to the wearable audio device, wherein the first HRTF and the second HRTF are based in part on the orientation of the peripheral device relative to the wearable device. 
     In one aspect, the first modified audio signal and the second modified audio signal are configured to simulate a first direct sound originating from a first virtual sound source proximate a center of the peripheral device. 
     In one aspect, generating the first modified audio signal and generating the second modified audio signal include simulating a first direct sound originating from a first virtual sound source proximate a position of the peripheral device within the environment and simulating a second direct sound originating from a second virtual sound source proximate the position of the peripheral device. 
     In one aspect, generating the first modified audio signal and generating the second modified audio signal include simulating surround sound. 
     In one aspect, generating the first modified audio signal and generating the second modified audio signal includes using the first HRTF and the second HRTF, respectively, for only a subset of all available audio frequencies and/or channels. 
     In one aspect, the first HRTF and the second HRTF are further configured to utilize localization data from a localization module within the environment corresponding to locations of a plurality of acoustically reflective surfaces within the environment. 
     In one aspect, generating the first modified audio signal includes simulating a first direct sound originating from a first virtual sound source proximate the peripheral device and simulating a primary reflected sound corresponding to a simulated reflection of the first direct sound off of a first acoustically reflective surface of the plurality of acoustically reflective surfaces. 
     In one aspect, generating the first modified audio signal includes simulating a secondary reflected sound corresponding to a simulated reflection of the primary reflected sound off of a second acoustically reflective surface of the plurality of acoustically reflective surfaces. 
     In one aspect, the first modified audio signal and the second modified audio signal correspond to video content displayed on the peripheral device. 
     In one aspect, the orientation of the wearable audio device relative to the peripheral device is determined using at least one sensor, wherein the at least one sensor is located on, in, or in proximity to the wearable audio device or the peripheral device, and the at least one sensor is selected from: a gyroscope, an accelerometer, a magnetometer, a global positioning sensor (GPS), a proximity sensor, a microphone, a lidar sensor, or a camera. 
     In another example, a method of simulating audio signals is provided, the method including: receiving, via a wearable audio device from a peripheral device, a first modified audio signal, wherein the first modified audio signal is modified using a first head-related transfer function (HRTF) based at least in part on an orientation of the wearable audio device relative to the peripheral device; receiving, via the wearable audio device from the peripheral device, a second modified audio signal, wherein the second modified audio signal is modified using a second head-related transfer function (HRTF) based at least in part on the orientation of the wearable audio device relative to the peripheral device; rendering the first modified audio signal using a first speaker of the wearable audio device; and rendering the second modified audio signal using a second speaker of the wearable audio device. 
     In an aspect, the method further includes: obtaining a position of a wearable audio device relative to the peripheral device within an environment and wherein modifying the first modified audio signal and modifying the second modified audio signal are based at least in part on a calculated distance between the position of the wearable audio device and a position of the peripheral device. 
     In an aspect, the method further includes obtaining an orientation of the peripheral device relative to the wearable audio device, wherein the first HRTF and the second HRTF are based in part on the orientation of the peripheral device. 
     In an aspect, the first modified audio signal and the second modified audio signal are configured to simulate a first direct sound originating from a first virtual sound source proximate a center of the peripheral device. 
     In an aspect, rendering the first modified audio signal and rendering the second modified audio signal include simulating a first direct sound originating from a first virtual sound source proximate a position of the peripheral device within the environment and simulating a second direct sound originating from a second virtual sound source proximate the position of the peripheral device. 
     In one aspect, generating the first modified audio signal and generating the second modified audio signal include simulating surround sound. 
     In one aspect, generating the first modified audio signal and generating the second modified audio signal includes using the first HRTF and the second HRTF, respectively, for only a subset of all available audio frequencies and/or channels. 
     In an aspect, the method further includes receiving localization data from a localization module within the environment; and determining locations of a plurality of acoustically reflective surfaces within the environment based on the localization data. 
     In an aspect, rendering the first modified audio signal includes simulating a first direct sound originating from a first virtual sound source proximate the peripheral device and simulating a primary reflected sound corresponding to a simulated reflection of the first direct sound off of a first acoustically reflective surface of the plurality of acoustically reflective surfaces. 
     In an aspect, rendering the first modified audio signal includes simulating a secondary reflected sound corresponding to a simulated reflection of the primary reflected sound off of a second acoustically reflective surface of the plurality of acoustically reflective surfaces. 
     In an aspect, the peripheral device includes a display configured to display video content associated with the first modified audio signal and second modified audio signal. 
     In an aspect, the orientation of the wearable audio device relative to the peripheral device is determined using at least one sensor, wherein the at least one sensor is located on, in, or in proximity to the wearable audio device or the peripheral device, and the at least one sensor is selected from: a gyroscope, an accelerometer, a magnetometer, a global positioning sensor (GPS), a proximity sensor, a microphone, a lidar sensor, or a camera. 
     In a further example, an audio system for simulating audio is provided, the system including a peripheral device configured to obtain or receive an orientation of a wearable audio device relative to the peripheral device within an environment, the peripheral device further configured to generate a first modified audio signal using a first head-related transfer function (HRTF) based on the orientation of the wearable audio device with respect to the peripheral device and generate a second modified audio signal using a second head-related transfer function (HRTF) based on the orientation of the wearable audio device with respect to the peripheral device; and, the wearable audio device. The wearable audio device includes a processor configured to receive the first modified audio signal and receive the second modified audio signal; a first speaker configured to render the first modified audio signal using the first speaker; and a second speaker configured to render the second modified audio signal using the second speaker. 
     These and other aspects of the various embodiments will be apparent from and elucidated with reference to the embodiment(s) described hereinafter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the various embodiments. 
         FIG. 1  is a schematic perspective view of an audio system according to the present disclosure. 
         FIG. 2A  is a schematic representation of the components of a wearable audio device according to the present disclosure. 
         FIG. 2B  is a schematic representation of the components of a peripheral device according to the present disclosure. 
         FIG. 3  is a schematic top plan view of the components of an audio system according to the present disclosure. 
         FIG. 4  is a schematic top plan view of the components of an audio system within an environment according to the present disclosure. 
         FIG. 5  is a schematic top plan view of the components of an audio system within an environment according to the present disclosure. 
         FIG. 6  is a schematic top plan view of the components of an audio system according to the present disclosure. 
         FIG. 7  is a schematic top plan view of the components of an audio system within an environment according to the present disclosure. 
         FIG. 8  is a schematic top plan view of the components of an audio system within an environment according to the present disclosure. 
         FIG. 9  is a schematic top plan view of the components of an audio system within an environment according to the present disclosure. 
         FIG. 10  is a flow chart illustrating the steps of a method according to the present disclosure. 
         FIG. 11  is a flow chart illustrating the steps of a method according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     The present disclosure relates to audio systems, methods, and computer program products which include a wearable audio device (e.g., headphones or earbuds) and a peripheral device, such as a mobile peripheral device (e.g., a smartphone or tablet computer). The wearable audio device and the peripheral device are capable of determining their respective positions and/or orientations within an environment as well as their respective positions and/or orientations with respect to each other. Once the relative positions and orientations between, e.g., the wearable audio device and the peripheral device are known, virtual sound sources may be generated at fixed positions and orientations relative to the peripheral device such that any change in position and/or orientation of the peripheral device produces a proportional change in the position and/or orientation of the virtual sound sources. Additionally, one or more orders of reflected audio paths (e.g., first order, and optionally also second order) may be simulated for each virtual sound source to increase the sense of realism of the simulated sources. Each sound path, e.g., direct sound paths, as well as the orders of reflected sound paths (e.g., the first order, and optionally the second order), can be produced by modifying the original audio signal using a plurality of left head-related transfer functions (HRTFs) and a plurality of right HRTFs to simulate audio as though it were perceived by the user&#39;s left and right ears, respectively, coming from each virtual sound source. 
     The term “wearable audio device”, as used in this application, in addition to its ordinary meaning to those with skill in the art, is intended to mean a device that fits around, on, in, or near an ear (including open-ear audio devices worn on the head or shoulders of a user) and that radiates acoustic energy into or towards the ear. Wearable audio devices are sometimes referred to as headphones, earphones, earpieces, headsets, earbuds or sport headphones, and can be wired or wireless. A wearable audio device includes an acoustic driver to transduce audio signals to acoustic energy, which could utilize air conduction and/or bone conduction techniques. The acoustic driver may be housed in an earcup. While some of the figures and descriptions following may show a single wearable audio device, having a pair of earcups (each including an acoustic driver) it should be appreciated that a wearable audio device may be a single stand-alone unit having only one earcup. Each earcup of the wearable audio device may be connected mechanically to another earcup or headphone, for example by a headband and/or by leads that conduct audio signals to an acoustic driver in the ear cup or headphone. A wearable audio device may include components for wirelessly receiving audio signals. A wearable audio device may include components of an active noise reduction (ANR) system. Wearable audio devices may also include other functionality such as a microphone so that they can function as a headset. While  FIG. 1  shows an example of an audio eyeglasses form factor, in other examples the headset may be an in-ear, on-ear, around-ear, or near-ear headset. In some examples, a wearable audio device may be an open-ear device that includes an acoustic driver to radiate acoustic energy towards the ear while leaving the ear open to its environment and surroundings. 
     The term “head related transfer function” or acronym “HRTF” as used herein, in addition to its ordinary meaning to those with skill in the art, is intended to broadly reflect any manner of calculating, determining, or approximating the binaural sound that a human ear perceives such that the listener can approximate the sound&#39;s position of origin in space. For example, a HRTF may be a mathematical formula or collection of mathematical formulas that can be applied or convolved with an audio signal such that a user listening to the modified audio signal can perceive the sound as originating at a particular point in space. These HRTFs, as referred to herein, may be generated specific to each user, e.g., taking into account that user&#39;s unique physiology (e.g., size and shape of the head, ears, nasal cavity, oral cavity, etc.). Alternatively, it should be appreciated that a generalized HRTF may be generated that is applied to all users, or a plurality of generalized HRTFs may be generated that are applied to subsets of users (e.g., based on certain physiological characteristics that are at least loosely indicative of that user&#39;s unique head related transfer function, such as age, gender, head size, ear size, or other parameters). In one example, certain aspects of the HRTFs may be accurately determined, while other aspects are roughly approximated (e.g., accurately determines the inter-aural delays, but coarsely determines the magnitude response). 
     The following description should be read in view of  FIGS. 1-9 .  FIG. 1  is a schematic view of audio system  100  according to the present disclosure. Audio system  100  includes a wearable audio device  102  and a peripheral device  104 . Wearable audio device  102  is intended to be a device capable of receiving an audio signal, e.g., modified audio signals  146 A- 146 B (shown in  FIGS. 2A and 2B ) discussed below, and producing or rendering that signal into acoustic energy within environment E and proximate a user or wearer&#39;s ear. In one example, as illustrated in  FIG. 1 , wearable audio device  102  comprises an eyeglass form factor audio device capable of rendering acoustic energy outside of and proximate to a user&#39;s ear. It should be appreciated that, in other examples, wearable audio device  102  can be selected from over-ear or in-ear headphones, earphones, earpieces, a headset, earbuds, or sport headphones. Peripheral device  104  can be selected from any electronic device capable of generating and/or transmitting an audio signal, e.g., modified audio signals  146 A- 146 B discussed below, to a separate device, e.g., wearable audio device  102 . In one example, as illustrated in  FIGS. 1 and 3-9 , peripheral device  104  is intended to be a tablet. However, it should be appreciated that peripheral device  104  can be selected from a smart phone, a laptop or personal computer, a case configured to matingly engage with and/or charge the wearable audio device  102 , or any other portable and/or movable computational device. 
     As illustrated in  FIG. 2A , wearable audio device  102  further includes first circuitry  106 . First circuitry  106  includes a first processor  108  and a first memory  110  configured to execute and store, respectively, a first set of non-transitory computer-readable instructions  112  to perform the various functions of first circuitry  106  and wearable audio device  102  as described herein. First circuitry  106  further includes a first communications module  114  configured to send and/or receive data, e.g., audio data, via a wired or wireless connection, e.g., data connection  142  (discussed below) with peripheral device  104 . In some examples, the audio data sent and/or received includes modified audio signals  146 A- 146 B discussed below. It should be appreciated that first communications module  114  can further include a first antenna  116  for the purpose of sending and/or receiving the data discussed above. Furthermore, although not illustrated, it should be appreciated that wearable audio device  102  can include a battery, capacitor, supercapacitor, or other power source located on, in, or in electronic communication with first circuitry  106 . 
     First circuitry  106  also includes at least one sensor, i.e., first sensor  118 . First sensor  118  can be located on, in, or in communication with wearable audio device  102 . First sensor  118  is a selected from at least one of: a gyroscope, an accelerometer, a magnetometer, a global positioning sensor (GPS), a proximity sensor, a microphone or plurality of microphones, a camera or plurality of cameras (e.g., front and rear mounted cameras), or any other sensor device capable of obtaining at least one of: a first position P 1  of wearable audio device  102  within environment E, a first position P 1  relative to peripheral device  104 ; a first orientation O 1  of the wearable audio device  102  relative to environment E; a first orientation O 1  of the wearable audio device  102  relative to peripheral device  104 ; or the distance between wearable audio device  102  and peripheral device  104 . First position P 1  and first orientation O 1  will be discussed below in further detail. Furthermore, first circuitry  106  can also include at least one speaker  120 . In one example, first sensor  118  is a camera or plurality of cameras, e.g., front and rear-mounted cameras, that are capable of obtaining image data of the environment E and/or the relative location and orientation of peripheral device  104  as will be discussed below. In one example, first circuitry  106  includes a plurality of speakers  120 A- 120 B configured to receive an audio signal, e.g., modified audio signals  146 A- 146 B (discussed below) and generate an audio playback APB to produce audible acoustic energy associated with the audio signal proximate a user&#39;s ear. 
     As illustrated in  FIG. 2B , peripheral device  104  further includes second circuitry  122 . Second circuitry  122  includes a second processor  124  and a second memory  126  configured to execute and store, respectively, a second set of non-transitory computer-readable instructions  128  to perform the various functions of second circuitry  122  and peripheral device  104  as described herein. Second circuitry  122  further includes a second communications module  130  configured to send and/or receive data, e.g., audio data, via a wired or wireless connection with wearable audio device  102  (discussed below) and/or with a device capable of connecting to the internet, e.g., a local router or cellular tower. In some examples, the audio data sent and/or received includes modified audio signals  146 A- 146 B discussed below. It should be appreciated that second communications module  130  can further include a second antenna  132  for the purpose of sending and/or receiving the data discussed above. Furthermore, although not illustrated, it should be appreciated that peripheral device  104  can include a battery, capacitor, supercapacitor, or other power source located on, in, or in electronic communication with second circuitry  122 . 
     Second circuitry  122  can also include at least one sensor, i.e., second sensor  134 . Second sensor  134  can be located on, in, or in communication with peripheral device  104 . Second sensor  134  is selected from at least one of: a gyroscope, an accelerometer, a magnetometer, a global positioning sensor (GPS), a proximity sensor, a microphone, a camera or plurality of cameras (e.g., front and rear cameras), or any other sensor device capable of obtaining at least one of: a second position P 2  of peripheral device  104  within environment E, a second position P 2  relative to wearable audio device  102 ; a second orientation O 2  of the peripheral device  104  relative to environment E; a second orientation O 2  of the peripheral device  104  relative to wearable audio device  102 ; or the distance between wearable audio device  102  and peripheral device  104 . Second position P 2  and second orientation O 2  will be discussed below in further detail. In one example, second sensor  134  is a camera or plurality of cameras, e.g., front and rear-mounted cameras, that are capable of obtaining image data of the environment E and/or the relative location and orientation of wearable audio device  102  as will be discussed below. 
     Furthermore, second circuitry  122  can also include at least one device speaker  136 , and a display  138 . In one example, at least one device speaker  136  is configured to receive an audio signal or a portion of an audio signal, e.g., modified audio signals  146 A- 146 B (discussed below) and generate an audio playback APB to produce audible acoustic energy associated with the audio signal at the second position P 2  of the peripheral device  104  at a fixed distance from the wearable audio device  102 . Display  138  is intended to be a screen capable of displaying video content  140 . In one example, display  138  is a Liquid-Crystal Display (LCD) and may also include touch-screen functionality, e.g., is capable of utilizing resistive or capacitive sensing to determine contact with, and position of, a user&#39;s finger against the screen surface. It should also be appreciated that display  138  can be selected from at least one of: a Light-Emitting Diode (LED) screen, an Organic Light-Emitting Diode (OLED) screen, a plasma screen, or any other display technology capable of presenting pictures or video, e.g., video content  140 , to a viewer or user. 
     As mentioned above, wearable audio device  102  and/or peripheral device  104  are configured to obtain their respective positions and orientations within environment E and/or relative to each other using first sensor  118  and second sensor  134 , respectively. In one example environment E is a room, e.g., a space defined by a floor surrounded by at least one wall and capped by a ceiling or roof and within which single positions can be modeled and defined by a three-dimensional Cartesian coordinate system as having X, Y, and Z, positions within the defined space associated with a length dimension, a width dimension, and a height dimension, respectively. Therefore, obtaining first position P 1  of wearable audio device  102  can be absolute within environment E, e.g., defined purely by its Cartesian coordinate within the room, or can be relative to the position of the other device, i.e., peripheral device  104 . 
     Similarly, each device can obtain its own orientation defined by a respective yaw, pitch, and roll within a spherical coordinate system with an origin point at the center of each device, where yaw includes rotation about a vertical axis through the device and orthogonal to the floor beneath the device, pitch includes rotation about a first horizontal axis orthogonal to the vertical axis and extending from the at least one wall of the room, and roll includes rotation about a second horizontal axis orthogonal to the vertical axis and the first horizontal axis. In one example, where first orientation O 1  of wearable audio device  102  and second orientation O 2  of peripheral device  104  are defined relative to each other, each device may determine a vector representative of a relative elevation between each device and a relative azimuth angle, which are based in part on the yaw, pitch, and roll of each device. It should also be appreciated that first orientation O 1  and second orientation O 2  can also be obtained absolutely within environment E, e.g., with respect to a predetermined and/or fixed position within environment E. 
     As mentioned above, the respective circuitries of the devices of audio system  100 , e.g., first circuitry  106  of wearable audio device  102  and second circuitry  122  of peripheral device  104 , are capable of establishing, and sending and/or receiving wired or wireless data over, a data connection  142 . For example, first antenna  116  of first communication module  114  is configured to establish data connection  142  with second antenna  132  of second communications module  130 . Data connection  142  can utilize one or more wired or wireless data protocols selected from at least one of: Bluetooth, Bluetooth Low-Energy (BLE) or LE Audio, Radio Frequency Identification (RFID) communications, Low-Power Radio frequency transmission (LP-RF), Near-Field Communications (NFC), or any other protocol or communication standard capable of establishing a permanent or semi-permanent connection, also referred to as paired connection, between first circuitry  106  and second circuitry  122 . It should be appreciated that data connection  142  can be utilized by first circuitry  106  of wearable audio device  102  and second circuitry  122  of peripheral device  104  to send and/or receive data relating to the respective positions and orientations of each device as discussed above, e.g., first position P 1 , second position P 2 , first orientation O 1 , second orientation O 2 , and the distance between devices, such that each device can be aware of the position and orientation of itself and/or the other devices within audio system  100 . Additionally, as mentioned above, data connection  142  can also be used to send and/or receive audio data, e.g., modified audio signals  146 A- 146 B (discussed below) between the devices of audio system  100 . 
     In addition to the ability to obtain respective positions and orientations of each device of audio system  100 , audio system  100  is also configured to render externalized sound to the user within environment E, using, for example, modified audio signals  146 A- 146 B (discussed below) that have been filtered or modified using at least one head-related transfer function (HRTF) (also discussed below). In one example of audio system  100 , sound externalization for use in augmented reality audio systems and programs is achieved by modeling an environment E, creating virtual sound sources at various positions within environment E, e.g., virtual sound sources  144 A- 144 G (collectively referred to as “plurality of virtual sound sources  144 ” or “virtual sound sources  144 ”), and modeling or simulating sound waves and their respective paths from the virtual sound sources  144  (shown in  FIGS. 3-9 ) to the position of the user&#39;s ears to simulate to the user perception of sound as though the virtual sound sources  144  were real or tangible sound sources, e.g., a physical speaker located at each virtual sound source position. For each modeled or simulated sound path, computational processing is used to apply or convolve at least one pair of HRTFs (one associated with the left ear and one associated with the right ear) to audio signals to generate modified audio signals  146 A- 146 B. Once the HRTFs have been applied and the modified audio signals  146 A- 146 B are generated, the modified audio signals  146 A- 146 B can be played through a plurality of speakers  120 A- 120 B (left and right speakers) of the wearable device  102  to trick the user&#39;s mind into thinking they are perceiving sound from an actual externalized source located at the positions of the respective virtual sound sources  144 . As will be explained below, the quality of the simulated realism of these modified audio signals  146 A- 146 B can increase by simulating first order and second order acoustic reflections from each virtual sound source within environment E, as well as attenuating or delaying the simulated signals to approximate time-of-flight of propagation of a sound signal through air. It should be appreciated that either wearable audio device  102  and/or peripheral device  104  can process, apply, or convolve the HRTFs to simulate the virtual sound sources as will be discussed herein. However, as the form factor, and therefore space for additional processing components, is typically limited in wearable audio devices, e.g., wearable audio device  102 , it should also be appreciated that the application or convolution of the HRTFs with the audio signals discussed is likely to be achieved by the circuitry of peripheral device  104  and then modified audio signals  146 A- 146 B can be sent or streamed to wearable audio device to be rendered as audio playback APB. 
     In some examples, the positions of each virtual sound source of plurality of virtual sound sources  144  with respect to the position of the wearable audio device  102  can be utilized to calculate and simulate a respective plurality of direct sound paths  148 A- 148 G (collectively referred to as “plurality of direct sound paths  148 ” or “direct sound paths  148 ”), i.e., at least one direct sound path  148  from each virtual sound source  144  directly to the user&#39;s ears. Each sound path can be associated with a calculated distance (e.g., calculated distance D 1  shown in  FIG. 3  and calculated distances D 2 -D 3  shown in  FIGS. 5 and 7 ) of the respective direct sound path  148  from the virtual sound source  144  to the wearable audio device  102 . As real sound wave propagation dissipates as a function of distance or radius from the origin point, the calculated distances can be used by the HRTFs to attenuate and/or delay the sound signals as a function of the calculated distance, e.g., as  1 /distance for each sound path discussed herein. For every direct sound path  148 , audio system  100  can utilize at least one of a plurality of left HRTFs  150  and a plurality of right HRTFs  152  to filter or modify the original audio signal to account for directionality and/or calculated distance. In one example, the HRTFs can utilize azimuth angle, elevation, and distance between each virtual sound source  144  and wearable audio device  102  to filter and/or attenuate the audio signals. It should be appreciated that, in one example, the left HRTFs and right HRTFs may be obtained from a predetermined database where the particular pair or singular HRTF that is chosen is chosen based on the particular relative azimuth angle and/or particular relative elevation between the devices. Thus, in some example implementations the respective HRTFs are stored as a database of filter coefficients for different azimuth angles and/or relative elevations rather than being calculated directly. 
     In one example, illustrated in  FIGS. 3 and 4 , audio system  100  is configured to simulate direct sound from a single virtual sound source  144 A. As shown in  FIG. 3 , audio system  100  includes wearable audio device  102  at first position P 1  and first orientation O 1 , and peripheral device  104  at second position P 2  and second orientation O 2 . As shown, a single virtual sound source  144 A is generated or simulated at a center C of peripheral device  104 . Virtual sound source  144 A is intended to simulate a center audio channel of a given audio signal along direct sound path  148 A. Additionally, as the positions of wearable audio device  102  and peripheral device  104  are known relative to each other or absolutely in environment E, the position of the virtual sound source  144 A is also known and therefore a distance between the first sound source  144 A and the wearable audio device  102  can be calculated, e.g., as calculated distance D 1  shown in  FIG. 3 . As discussed above, and illustrated in  FIG. 4 , audio system  100  can modify the audio signal to simulate center channel audio as though it was generated at a position and distance corresponding with the center C of peripheral device  104  by applying or convolving the original center channel audio signal with a left HRTF  150  and a right HRTF  152  into modified audio signals  146 A- 146 B which can be played through left and right speakers (e.g., speakers  120 A and  120 B shown in  FIG. 2 ) to simulate the direct sound path  148 A from virtual sound source  144 A to the user&#39;s left and right ears, respectively. It should be appreciated that, in  FIG. 4 , direct sound path  148 A has been schematically split to illustrate how direct sound path  148 A can represent both a modified audio signal  146 A that has been modified by left HRTF  150  and a modified audio signal  146 B that has been modified by right HRTF  152 . For simplicity, the illustrations and explanations that follow will refer only to individual sound paths; however, it should be appreciated that each sound path can schematically represent two separate modified audio signals that have been modified using left and right HTRFs as discussed above. 
     Similarly to virtual sound source  144 A associated with a center channel audio signal, left channel and right channel audio signals may be simulated through additional virtual sound sources, e.g.,  144 B and  144 C, as illustrated in  FIG. 5 . As illustrated, a virtual sound source  144 B can be generated proximate to a left side L of peripheral device  104  to simulate left channel audio and a virtual sound source  144 C can be generated proximate to a right side R of peripheral device  104  to simulate right channel audio. It should also be appreciated that these audio signals can be generated such that a phantom center channel is created equidistant between virtual sound sources  144 B and  144 C, such that simulating the center channel audio through virtual sound source  144 A is not necessary. In one example, as illustrated in  FIG. 5 , virtual audio sources  144 B and  144 C can be positioned such that, when using first position P 1  of wearable audio device  102  as an origin point, the angle α created between virtual sound sources  144 B and  144 C is approximately 30 degrees, e.g., −15 to +15 degrees about a center line CL. It should be appreciated that this angle can be selected from any angle within the range between 0-180 degrees, e.g., −75 to +75 degrees, −50 to +50 degrees, −30 to +30 degrees, or −5 to +5 degrees about center line CL. 
     Additionally, other virtual sound source configurations are possible. For example,  FIG. 6  illustrates a configuration of virtual sound sources  144  which simulate a 5.1 surround sound system. For example, virtual audio sources  144 A- 144 C are simulated in space in front of wearable audio device  102  and proximate peripheral device  104  to simulate front-center, front-left, and front-right channel audio signals as discussed above. To create the 5.1 surround sound effect, two additional virtual sound sources, e.g.,  144 D and  144 E are simulated behind the wearable audio device  102  to simulate rear-left and rear-right audio signals, respectively. It should be appreciated that other arrangements and configurations are possible, e.g., additional virtual sound sources can be added such that audio system  100  can simulate 7.1 and 9.1 surround sound systems, and although not illustrated, can also include at least one simulated subwoofer to provide simulated base channel audio. 
     Alternatively, and although not illustrated, it should be appreciated that one or more virtual sound sources  144  within any of the foregoing exemplary configurations may be replaced by a real sound source e.g., a real tangible speaker placed within environment E at the approximate location of the virtual sound source that it is intended to replace. For example, the center channel audio signal, rendered at the locations indicated for virtual sound source  144 A, could be replaced, i.e., not generated virtually at that position and the at least one device speaker  136  can render audio playback APB at the location of peripheral device  104  where the audio playback APB only includes center channel audio. Similarly, as it may be difficult to simulate directionality of audio corresponding to a base audio channel, a real subwoofer can be placed within environment E to replace a virtual equivalent base sound source. In addition to, or in the alternative to, the foregoing, it should be appreciated that one or more virtual sound sources  144  within any of the foregoing exemplary configurations can be rendered by wearable audio device  102  without being virtualized or spatialized as discussed herein. For example, in a configuration that utilizes left, right, and center audio channels, as discussed above, audio system  100  can choose to virtualize or spatialize any of those channels by generating a virtual audio source  144  within the environment E that simulates one or more of those channels. However, audio system  100  can, in addition to, or in the alternative to spatializing one or more of those channels, render audio at the speakers of the wearable audio device  102  that is unspatialized, e.g., one or more of those channels may be rendered to audible sound by the wearable audio device  102  and perceived by the user as though it were coming from inside the user&#39;s head. 
     In addition, in some implementations, the techniques described herein to spatially pin audio to a given location (such as the center of the display of the peripheral device) could separate the audio to be spatially pinned by frequency and/or channel, such that portions of the audio is spatially pinned and other portions are not. For instance, the portions of the audio that relate to low frequencies, such as those for a subwoofer channel, could be excluded from being spatialized using the techniques variously described herein as those low frequencies are relatively spatially/directionally agnostic compared to other frequencies. In other words, in the case of low frequencies and/or a subwoofer channel, there is little information a user&#39;s brain can use to localize the source of the low frequencies and/or subwoofer channel, and so including those frequencies and/or that channel when transforming the audio to be spatially pinned would add computational cost with little to no psychoacoustic benefit (as the user wouldn&#39;t be able to tell where those low frequencies and/or subwoofer channel was coming from, anyway). This is why subwoofers in audio systems can generally be placed anywhere in a room, as low frequencies are directionally agnostic. In some such implementations, the techniques include separating out the frequency, channel, and/or portion (e.g., low frequencies and/or the subwoofer channel) prior to performing the spatial pinning as variously described herein, performing the spatial pinning for the remainder of the frequencies, channels, and/or portions, and then combining the non-spatially pinned aspect (e.g., low frequencies and/or the subwoofer channel) with the spatially pinned aspect (e.g., all other frequencies and/or all other channels). 
     In the following examples, corresponding to  FIGS. 7-9 , only two virtual sound sources will be described and illustrated, i.e., virtual sound sources  144 B and  144 C; however, it should be appreciated that, as set forth above, other configurations having more or less virtual sound sources are possible as well as configurations having one or more subwoofers to simulate one or more base channels. As discussed above, the position and orientation of each virtual sound source  144  is pinned, locked, or otherwise spatially fixed with respect to the position and orientation of the peripheral device  104 . In other words, should the peripheral device  104  move, rotate, pivot, tilt, or otherwise change position, location, or orientation within environment E or with respect to the wearable audio device  102 , the plurality of virtual sound sources  144  will move, rotate, pivot, tilt, or otherwise change position, location, or orientation proportionally such that the position and orientation of each virtual sound source  144  is fixed with respect to the peripheral device  104 . As the devices of audio system  100  are capable of obtaining their relative positions and orientations with respect to each other or within the environment E, the distances between devices and/or virtual sound sources  144  can be utilized by the HRTFs to attenuate and/or delay the sound signals to simulate the actual time-of-flight that a real sound wave would experience when propagating through air from the position of each respective virtual sound source  144 . Thus, the real world directionality as well as the real world time-delay that would be experienced by a plurality of real external sources can be simulated to the wearer, user, or listener through wearable audio device  102  by altering or modifying the original audio signals using left HRTF  150  and right HRTF  152  into modified audio signals  146 A and  146 B. Additionally, although in some examples, the positions of the virtual sound sources within environment E are proportionately pinned to or fixed to the position and orientation of peripheral device  104 , e.g., will move, rotate, pivot, tilt, or otherwise change position, location, or orientation proportionately to movement of peripheral device  104 , in some examples, the height of each virtual sound source is clamped or limited to certain heights with respect to the floor beneath the user. For example, should the user pivot peripheral device 45 degrees in a rotation that would place the screen of peripheral device substantially facing the ceiling above the user, any front virtual sound sources (e.g., in a 5.1 surround sound configuration) that have been spatialized or virtualized on the opposing side or back side of the position of the peripheral device will pivot proportionately, and may be proximate to or within the floor beneath the user, while the rear virtual sound sources that have been spatialized or virtualized behind the user will pivot proportionately and may be proximate to or within the ceiling above the user. Thus, in some examples, the height of the virtual sound sources, e.g., at least the front and rear simulated virtual sound sources, may be fixed or locked to a particular height from the floor, e.g., the approximate height of the wearable audio device  102  from the floor. In other example, the height of virtual sound sources may be fixed or locked relative to the height of a pedestal or other object within environment E. 
     During operation, as illustrated in  FIG. 7 , audio system  100  can simulate two virtual sound sources, e.g., virtual sound sources  144 B and  144 C corresponding to left and right channel audio signals, where the virtual sound sources are spatially pinned, locked, or otherwise fixed with respect to second orientation O 2  and second position P 2  of peripheral device  104 . As illustrated, should the user rotate or otherwise alter the orientation of peripheral device  104 , e.g., rotate peripheral device  104  clockwise approximately 45 degrees about second position P 2 , the position of virtual sound sources  144 B and  144 C will revolve at fixed distances from the peripheral device  104  and about position P 2  approximately 45 degrees such that after rotation of peripheral device  104 , the positions of virtual sound sources  144 B and  144 C with respect to peripheral device  104  are the same as they were before the rotation. Notably, by rotating the peripheral device  104  45 degrees while the user maintains their original head position, i.e., first position P 1  and first orientation O 1  of wearable audio device  102 , the position of each virtual sound source  144 B and  144 C with respect to the wearable audio device  102  will be altered. For example, when rotating peripheral device  104  clockwise approximately 45 degrees, as shown in  FIG. 7 , virtual sound source  144 B will move away from wearable audio device  102  while virtual sound source  144 C will move closer to wearable audio device  102 . Said another way, calculated distance D 2  will increase while calculated distance D 3  will decrease, as shown. Thus, to account for the rotation of peripheral device  104  with respect to wearable audio device  102 , left HRTF  150  can include the change in calculated distance D 2  of virtual sound source  144 B to simulate an increase in distance to the wearable audio device  102  while right HRTF  152  can include the change to calculated distance D 3  of virtual sound source  144 C to simulate a decrease in distance to wearable audio device  102 . As discussed above, it should be appreciated that any number of virtual sound sources  144  may be simulated in any of the exemplary configurations above, and each virtual sound source  144  can be spatially pinned, locked, or fixed with respect to the peripheral device  104  as disclosed herein. Furthermore, although the foregoing example merely discloses a simple rotation of peripheral device  104  45 degrees in a clockwise rotation, more complex changes in orientation or position, e.g., tilting, moving, pivoting, or any combination of these motions can be accounted for in a similar manner as described above. 
     In another example, audio system  100  may utilize localization data to further increase the simulated realism of the externalized and/or virtualized sound sources  144 . As mentioned above, in addition to simulating direct sound paths from each virtual sound source  144 , one way to increase the realism of the simulated sound is to add additional virtual sound sources  144  which simulate primary and secondary reflections that real audio sources produce when propagating sound signals reflect off of acoustically reflective surfaces and back to the user. In other words, real sound sources create spherical waves, not just directional waves, which reflect off, e.g., acoustically reflective surfaces  154 A- 154 D (collectively referred to as “acoustically reflective surfaces  154 ” or “surfaces  154 ”), which can include but are not limited to walls, floors, ceilings, and other acoustically reflective surfaces such as furniture. Therefore, localization refers to the process of obtaining data of the immediate or proximate area or environment E surrounding the user, e.g., surrounding the wearable audio device  102  and/or the peripheral device  104 , which would indicate the locations, orientations, and/or acoustically reflective properties of the objects within the user&#39;s environment E. Once located, reflective paths may be calculated between each virtual sound source  144  and each surface  154 . The point where the paths contact each surface  154 , herein referred to as contact points CP, can be utilized to generate a new virtual sound source which, when simulated, produces sound that simulates an acoustic reflection of the original virtual sound source  144 . One way to generate these new virtual sound sources, is to create mirrored virtual sound sources for each virtual sound source, where the mirrored virtual sound sources are mirrored about the acoustically reflective surface  154  as will be described with respect to  FIG. 8  below. It should be appreciated that, to aid in obtaining localization data regarding the environment E surrounding the user, wearable audio device  102 , and/or peripheral device  104 , audio system  100  can further include a localization module  156  (shown in  FIGS. 2A and 2B ) which can be provided as a separate device or may be integrated within wearable audio device  102  or peripheral device  104 . For example, a separate localization module  156  can be provided where the separate localization module  156  is selected from at least one of: a rangefinder (e.g., a LIDAR sensor), a proximity sensor, a camera or plurality of cameras, a global positioning sensor (GPS), or any sensor, device, component, or technology capable of obtaining, collecting, or generating localization data with respect to the location of the user, the wearable audio device  102 , the peripheral device  104 , and the acoustically reflective surfaces  154 . In one example, localization module  156  includes at least one camera integrated within either wearable audio device  102  or peripheral device  104 , e.g., as first sensor  118  or second sensor  134 . The localization module  156  can also include or employ an artificial neural network, deep learning engine or algorithm, or other machine learning algorithm trained to visually detect the acoustic properties, the locations, and the orientations of the acoustically reflective surfaces  154  within environment E from the image data captured by the camera. In another example, localization module  156  is arranged to collect data related to the reverberation time and/or acoustic decay characteristics of the environment in which the user, wearable audio device  102 , or peripheral device  104  are located. For example, localization module  156  may include a dedicated speaker and can be configured to produce a specified sound signal (e.g., a “ping” or other signal outside of the range of human hearing) and measure the reflected response (e.g., with a dedicated microphone). In one example, an absorption coefficient is calculated from the reverberation time or other characteristics of the environment as whole, and applied to the acoustically reflective surfaces  154  as an approximation. If the sound signal is specifically directed or aimed at the acoustically reflective surfaces  154 , then the differences between the original signal and the initially received reflections can be used to calculate an absorption coefficient of the acoustically reflective surfaces  154 . In one example, localization module  156  includes a global positioning system (GPS) sensor, e.g., embedded in the wearable audio device  102  or peripheral device  104  and localization module  156  can selectably utilize data from acoustically reflective surfaces  154  that are within some threshold distance of each virtual sound source  144 . 
     Once localization data is obtained using, e.g., localization module  156 , and in addition to direct sound paths  148 A and  148 B discussed above, paths between each virtual sound source  144  and each acoustically reflective surface  154  can be determined. At the junction between each determined path and each acoustically reflective surface  154 , there is a contact point CP. In one example, as illustrated in  FIG. 8  in a top plan view of audio system  100  within environment E, audio system  100  includes primary mirrored virtual sound sources  158 A and  158 B (collectively referred to as “primary mirrored virtual sound sources  158 ” or primary mirrored sources  158 ″). Each primary mirrored virtual sound source  158 , is a new virtual sound source generated at a position equivalent to the position of the original virtual sound source  144  and mirrored about an acoustically reflective surface  154 . For example, as illustrated, a path (shown by a dashed line in  FIG. 8 ) between virtual sound source  144 B and acoustically reflective surface  154 A (illustrated as a wall), is determined. The point where the determined path meets acoustically reflective surface  154 A is labelled as a contact point CP. A copy of virtual sound source  144 B is generated as primary mirrored virtual sound source  158 A at a position equivalent to the position of virtual sound source  144 B after being mirrored about acoustically reflected surface  154 A. Once generated at the position illustrated, simulated sound generated from the position of this primary mirrored sound source  158 A, simulates a first order or primary reflected sound path  160 A (shown by a dotted line in  FIG. 8 ) which simulates sound from virtual sound source  144 B as though it was generated within environment E and reflected off acoustically reflective surface  154 A to the location of the user&#39;s ears, i.e., the approximate location of wearable audio device  102 . Similar paths can be determined and simulated to generate a primary mirrored virtual sound source  158 B corresponding to a first order or primary reflected sound path  160 B for virtual sound source  144 C. 
     Similarly, audio system  100  can generate secondary mirrored virtual sound sources  162 A- 162 B (collectively referred to as “secondary mirrored virtual sound sources  162 ” or secondary mirrored sources  162 ″). Each secondary mirrored virtual sound source  162 , is a new virtual sound source generated at a position equivalent to the position of the original virtual sound source  144  and mirrored about a different acoustically reflective surface  154 . For example, as illustrated, a two-part path (shown by two dashed lines in  FIG. 8 ), i.e., where a first part extends from virtual sound source  144 B to acoustically reflective surface  154 A (illustrated as a wall), and a second part extends from the termination of the first part of the path to a second acoustically reflective surface  154 B (illustrated as a wall) is determined. The point where the second part of the determined path meets acoustically reflective surface  154 B is labelled as a contact point CP. A copy of virtual sound source  144 B is generated as secondary mirrored virtual sound source  162 A at a position equivalent to the position of virtual sound source  144 B after being mirrored about acoustically reflected surface  154 B. Once generated at the position illustrated, simulated sound generated from the position of this secondary mirrored sound source  162 A, simulates a second order or secondary reflected sound path  164 A (shown by a dotted line in  FIG. 8 ) which simulates sound from virtual sound source  144 B as though it was generated within environment E and reflected off acoustically reflective surface  154 A and acoustically reflected surface  154 B to the location of the user&#39;s ears, i.e., the approximate location of wearable audio device  102 . Similar paths can be determined and simulated to generate a secondary mirrored virtual sound source  162 B corresponding to a second order or secondary reflected sound path  164 B reflected off acoustically reflective surface  154 A and acoustically reflective surface  154 C to simulate second order reflected audio of virtual sound source  144 C. 
     Similarly to the example described above with respect to  FIG. 7 , the primary mirrored virtual sound sources  158  and the secondary mirrored virtual sound sources  162  are pinned or otherwise spatially locked with respect to the orientation and position of peripheral device  104 . In other words, should the peripheral device  104  move, rotate, pivot, tilt, or otherwise change position, location, or orientation within environment E or with respect to the wearable audio device  102 , the plurality of virtual sound sources  144  within environment E will move, rotate, pivot, tilt, or otherwise change position, location, or orientation proportionally such that the position and orientation of each virtual sound source  144  is fixed with respect to the peripheral device  104 . As the locations, position, and/or orientations of the virtual sound sources  144  will change with peripheral device  104 , each primary mirrored virtual sound source  158  and each secondary mirrored virtual sound source will also move such that they continue to simulate reflections of virtual sound sources  144  about each acoustically reflective surface. 
     It should be appreciated that primary reflected sound paths  160  and secondary reflected sound paths  164  can be simulated using primary mirrored virtual sound sources  158  and secondary mirrored virtual sound sources  162  for every virtual sound source configuration discussed above, e.g., 5.1, 7.1, and 9.1 surround sound configurations as well as configurations which include at least one virtual subwoofer associated with base channel audio signals. Additionally, the present disclosure is not limited to primary and secondary reflections. For example, higher order reflections are possible, e.g., third order reflections, fourth order reflections, fifth order reflections, etc., are possible; however, as additional order reflections and therefore the number of virtual sound sources simulated increases, the computational processing power and processing time scales exponentially. In one example, audio system  100  is configured to simulate six virtual sound sources  144 , e.g., corresponding to a 5.1 surround sound configuration. For each virtual sound source  144 , a direct sound path  148  is calculated. For each virtual sound source  144  there are six first order or primary reflected sound paths  160 , corresponding to a first order reflection off of four walls, a ceiling, and a floor (e.g., acoustically reflective surfaces  154 ). Each first order reflected path may again reflect off of the other five remaining surfaces  154  producing an exponential number of virtual sources and reflected sound paths. It should be appreciated that, in some example implementations of audio system  100 , the number of second order reflections  164  is dependent on the geometry of the environment E, e.g., the shape of the room with respect to the position of the wearable audio device  102  and the virtual sound sources  144 . For example, in a rectangular room geometry, once a first order or primary reflected sound path  160  is selected, certain second order reflections  164  may not be physically possible, e.g., where the contact points CP would need to be positioned outside of the room to obtain a valid second order reflection path. Thus, in an example with a rectangular room geometry, it should be appreciated that rather than simulating five secondary reflected sound paths  164  for each first order reflected sound path  160 , only three secondary reflected sound paths  164  may be simulated to account for invalid second order reflections  164  caused by the particular room geometry. For example, rather than simulating six first order reflections  160  and thirty second order reflections  164  (e.g., where each of the six first order sound paths  160  are each reflected off of the five remaining walls), audio system  100  can simulate six first order reflections  160  and only eighteen secondary reflected sound paths  164  (e.g., each of the six first order reflections  160  off of three of the five remaining walls). It should also be appreciated that audio system  100  can be configured to perform a validity test across all simulated paths to ensure that the path from each simulated source to, e.g., the wearable audio device  102  is a valid path, i.e., is physically realizable dependent on the geometry of the environment E. 
     Additionally, due to the potential processing power required to generate these first order and second order reflections in real-time, in one example, audio system  100  utilizes the processing capacity of second circuitry  122  of peripheral device  104 , e.g., using second processor  124 , second memory  126  and/or second set of non-transitory computer-readable instructions  128 . However, it should be appreciated that, in some example implementations of audio system  100 , audio system  100  can utilize the processing capacity of first circuitry  106  of wearable audio devices  102  to simulate the first and second order reflected sound sources discussed herein, e.g., using first processor  108 , first memory  110 , and/or first set of non-transitory computer-readable instructions  112 . Furthermore, it should be appreciated that audio system  100  can split the processing load between first circuitry  106  and second circuitry  122  in any conceivable combination. 
     During operation, as illustrated in  FIG. 9 , audio system  100  can simulate two virtual sound sources, e.g., virtual sound sources  144 B and  144 C corresponding to left and right channel audio signals, where the virtual sound sources are spatially pinned, locked, or otherwise fixed with respect to second orientation O 2  and second position P 2  of peripheral device  104 . As illustrated, should the user rotate or otherwise alter the orientation of peripheral device  104 , e.g., rotate peripheral device  104  clockwise approximately 45 degrees about second position P 2 , the position of virtual sound sources  144 B and  144 C will revolve at fixed distances from the peripheral device  104  and about position P 2  approximately 45 degrees such that after rotation of peripheral device  104 , the positions of virtual sound sources  144 B and  144 C with respect to peripheral device  104  are the same as they were before the rotation. Notably, by rotating the peripheral device  104  45 degrees while the user maintains their original head position, i.e., first position P 1  and first orientation O 1  of wearable audio device  102 , the positions of each virtual sound source  144 B and  144 C, the positions of each primary mirrored sound source  158 , and the positions of each secondary mirrored sound source  162  with respect to the wearable audio device  102  will be altered. For example, when rotating peripheral device  104  clockwise approximately 45 degrees, as shown in  FIG. 9 , virtual sound source  144 B will move away from wearable audio device  102  while virtual sound source  144 C will move closer to wearable audio device  102 . Additionally, these changes result in proportional mirrored changes to each primary mirrored virtual sound source  158  and each secondary mirrored virtual sound source  162  to account for movement of the virtual sound sources  144  with respect to the position P 1  of wearable audio device  102 . Thus, at least one left HRTF  150  can include the change in the calculated distance of virtual sound source  144 B to simulate an increase in distance to the wearable audio device  102 , at least one left HRTF  150  can include the change in the calculated distance of primary mirrored virtual sound source  158 A to simulate an increase in distance to the wearable audio device  102 , and at least one left HRTF  150  can include the change in the calculated distance of secondary mirrored virtual sound source  162 A to simulate an increase in distance to the wearable audio device  102 . Similarly, at least one right HRTF  150  can include the change in the calculated distance of virtual sound source  144 B to simulate an increase in distance to the wearable audio device  102 , at least one left HRTF  150  can include the change in the calculated distance of primary mirrored virtual sound source  158 A to simulate an increase in distance to the wearable audio device  102 , and at least one left HRTF  150  can include the change in the calculated distance of secondary mirrored virtual sound source  162 A to simulate an increase in distance to the wearable audio device  102 . Similar modifications can be made using left HRTFs  150  and right HRTFs  152  based on the changes in position and/or orientation of virtual sound source  144 C. Furthermore, although the foregoing example merely discloses a simple rotation of peripheral device  104  45 degrees in a clockwise rotation, more complex changes in orientation or position, e.g., tilting, moving, pivoting, or any combination of these motions can be accounted for in a similar manner as described above. 
       FIGS. 10 and 11  illustrate exemplary steps of method  200  according to the present disclosure. Method  200  includes, for example: receiving, via a wearable audio device  102  from a peripheral device  104 , a first modified audio signal  146 A, wherein the first modified audio signal  146 A is modified using a first head-related transfer function (HRTF)  150  based at least in part on an orientation O 1  of the wearable audio device  102  relative to the peripheral device  104  (step  202 ); receiving, via the wearable audio device  102  from the peripheral device  104 , a second modified audio signal  146 B, wherein the second modified audio signal  146 B is modified using a second head-related transfer function (HRTF)  152  based at least in part on the orientation O 1  of the wearable audio device  102  relative to the peripheral device  104  (step  204 ); obtaining a position P 1  of a wearable audio device  102  relative to the peripheral device  104  within an environment E and wherein modifying the first modified audio signal  146 A and modifying the second modified audio signal  146 B are based at least in part on a calculated distance D 1 -D 3  between the position P 1  of the wearable audio device  102  and a position P 2  of the peripheral device  104  (step  206 ); obtaining an orientation O 2  of the peripheral device  104  relative to the wearable audio device  102 , wherein the first HRTF  150  and the second HRTF  152  are based in part on the orientation O 2  of the peripheral device  104  (step  208 ); rendering the first modified audio signal  146 A using a first speaker  120 A of the wearable audio device  102  (step  210 ); and rendering the second modified audio signal  146 B using a second speaker  120 B of the wearable audio device  102  (step  212 ). Optionally, method  200  may further include: receiving localization data from a localization module  156  within the environment E (step  214 ); and determining locations of a plurality of acoustically reflective surfaces  154  within the environment E based on the localization data (step  216 ). 
     All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and/or ordinary meanings of the defined terms. 
     The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.” 
     The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified. 
     As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of” or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of” “only one of,” or “exactly one of.” 
     As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. 
     It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited. 
     In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of” shall be closed or semi-closed transitional phrases, respectively. 
     The above-described examples of the described subject matter can be implemented in any of numerous ways. For example, some aspects may be implemented using hardware, software or a combination thereof. When any aspect is implemented at least in part in software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single device or computer or distributed among multiple devices/computers. 
     The present disclosure may be implemented as a system, a method, and/or a computer program product at any possible technical detail level of integration. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present disclosure. 
     The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire. 
     Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device. 
     Computer readable program instructions for carrying out operations of the present disclosure may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, configuration data for integrated circuitry, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++, or the like, and procedural programming languages, such as the “C” programming language or similar programming languages. The computer readable program instructions may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user&#39;s computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some examples, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present disclosure. 
     Aspects of the present disclosure are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to examples of the disclosure. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions. 
     The computer readable program instructions may be provided to a processor of a, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram or blocks. 
     The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various examples of the present disclosure. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the blocks may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions. 
     Other implementations are within the scope of the following claims and other claims to which the applicant may be entitled. 
     While various examples have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the function and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the examples described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific examples described herein. It is, therefore, to be understood that the foregoing examples are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, examples may be practiced otherwise than as specifically described and claimed. Examples of the present disclosure are directed to each individual feature, system, article, material, kit, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, and/or methods, if such features, systems, articles, materials, kits, and/or methods are not mutually inconsistent, is included within the scope of the present disclosure.