Patent Publication Number: US-2023132415-A1

Title: Machine learning-based audio manipulation using virtual backgrounds for virtual meetings

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to computer networks, and, more particularly, to machine learning-based audio manipulation using virtual backgrounds for virtual meetings. 
     BACKGROUND 
     Virtual meetings, by leveraging videoconference technologies, have become increasingly used. This is in part due to work environments&#39; continued evolution towards remote work, where virtual meetings have become nearly the primary means for collaboration, productivity, etc. (and as substitutes for in-person meetings). In addition to work, virtual meetings have been used more and more for non-work settings, including for class instruction and connecting friends and family (to re-connect, share, and build memories). 
     Videoconference technologies have allowed participants to apply a virtual background (e.g., a masking) to their video feeds, allowing participants to replace or disguise their physical backgrounds with different images. Participants, recently, have also started using virtual backgrounds to express themselves by selecting images that match their personalities, reflects their moods, etc. These virtual backgrounds, due to solely being based on one of the five senses, vision, are limited in the amount of immersion and customization they are able to provide. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The embodiments herein may be better understood by referring to the following description in conjunction with the accompanying drawings in which like reference numerals indicate identically or functionally similar elements, of which: 
         FIG.  1    illustrates an example communication network; 
         FIG.  2    illustrates an example network device/node; 
         FIG.  3    illustrates various example components of a videoconferencing system; 
         FIG.  4    illustrates an example display of a virtual meeting (or a videoconference); 
         FIGS.  5 A- 5 C  illustrate an example architecture for machine learning-based audio manipulation using virtual backgrounds for virtual meetings; 
         FIGS.  6 A- 6 B  illustrate example virtual background images; 
         FIG.  7    illustrates an example rotating virtual background; 
         FIG.  8    illustrates an example animated virtual background; 
         FIG.  9    illustrates an example an example virtual meeting multi-user mode; and 
         FIG.  10    illustrates an example simplified procedure for machine learning-based audio manipulation using virtual backgrounds for virtual meetings in accordance with one or more embodiments described herein. 
     
    
    
     DESCRIPTION OF EXAMPLE EMBODIMENTS 
     Overview 
     According to one or more embodiments of the disclosure, a videoconference service determines a selection of a virtual background for a videoconference from a particular participant of a plurality of participants in the videoconference. The videoconference service determines an audio context filter that is associated with a visual context of the virtual background. The videoconference service modifies an audio stream of the videoconference into a modified audio stream according to the audio context filter. The videoconference service presents, to the plurality of participants during the videoconference, the particular participant using the virtual background and the modified audio stream. In an embodiment, the videoconference service ascertains the visual context of the virtual background based on applying a machine learning model to the virtual background. 
     Other embodiments are described below, and this overview is not meant to limit the scope of the present disclosure. 
     DESCRIPTION 
     A computer network is a geographically distributed collection of nodes interconnected by communication links and segments for transporting data between end nodes, such as personal computers and workstations, or other devices, such as sensors, etc. Many types of networks are available, ranging from local area networks (LANs) to wide area networks (WANs). LANs typically connect the nodes over dedicated private communications links located in the same general physical location, such as a building or campus. WANs, on the other hand, typically connect geographically dispersed nodes over long-distance communications links, such as common carrier telephone lines, optical lightpaths, synchronous optical networks (SONET), synchronous digital hierarchy (SDH) links, and others. The Internet is an example of a WAN that connects disparate networks throughout the world, providing global communication between nodes on various networks. Other types of networks, such as field area networks (FANs), neighborhood area networks (NANs), personal area networks (PANs), enterprise networks, etc. may also make up the components of any given computer network. In addition, a Mobile Ad-Hoc Network (MANET) is a kind of wireless ad-hoc network, which is generally considered a self-configuring network of mobile routers (and associated hosts) connected by wireless links, the union of which forms an arbitrary topology. 
       FIG.  1    is a schematic block diagram of an example simplified computing system  100  illustratively comprising any number of client devices  102  (e.g., a first through nth client device), one or more servers  104 , and one or more databases  106 , where the devices may be in communication with one another via any number of networks  110 . The one or more networks  110  may include, as would be appreciated, any number of specialized networking devices such as routers, switches, access points, etc., interconnected via wired and/or wireless connections. For example, devices  102 - 104  and/or the intermediary devices in network(s)  110  may communicate wirelessly via links based on WiFi, cellular, infrared, radio, near-field communication, satellite, or the like. Other such connections may use hardwired links, e.g., Ethernet, fiber optic, etc. The nodes/devices typically communicate over the network by exchanging discrete frames or packets of data (packets  140 ) according to predefined protocols, such as the Transmission Control Protocol/Internet Protocol (TCP/IP) other suitable data structures, protocols, and/or signals. In this context, a protocol consists of a set of rules defining how the nodes interact with each other. 
     Client devices  102  may include any number of user devices or end point devices configured to interface with the techniques herein. For example, client devices  102  may include, but are not limited to, desktop computers, laptop computers, tablet devices, smart phones, wearable devices (e.g., heads up devices, smart watches, etc.), set-top devices, smart televisions, Internet of Things (IoT) devices, autonomous devices, collaboration endpoints, or any other form of computing device capable of participating with other devices via network(s)  110 . 
     Notably, in some embodiments, servers  104  and/or databases  106 , including any number of other suitable devices (e.g., firewalls, gateways, and so on) may be part of a cloud-based service. In such cases, the servers and/or databases  106  may represent the cloud-based device(s) that provide certain services described herein, and may be distributed, localized (e.g., on the premise of an enterprise, or “on prem”), or any combination of suitable configurations, as will be understood in the art. 
     Those skilled in the art will also understand that any number of nodes, devices, links, etc. may be used in computing system  100 , and that the view shown herein is for simplicity. Also, those skilled in the art will further understand that while the network is shown in a certain orientation, the computing system  100  is merely an example illustration that is not meant to limit the disclosure. 
     Notably, web services can be used to provide communications between electronic and/or computing devices over a network, such as the Internet. A web site is an example of a type of web service. A web site is typically a set of related web pages that can be served from a web domain. A web site can be hosted on a web server. A publicly accessible web site can generally be accessed via a network, such as the Internet. The publicly accessible collection of web sites is generally referred to as the World Wide Web (WWW). 
     Also, cloud computing generally refers to the use of computing resources (e.g., hardware and software) that are delivered as a service over a network (e.g., typically, the Internet). Cloud computing includes using remote services to provide a user&#39;s data, software, and computation. 
     Moreover, distributed applications can generally be delivered using cloud computing techniques. For example, distributed applications can be provided using a cloud computing model, in which users are provided access to application software and databases over a network. The cloud providers generally manage the infrastructure and platforms (e.g., servers/appliances) on which the applications are executed. Various types of distributed applications can be provided as a cloud service or as a Software as a Service (SaaS) over a network, such as the Internet. 
       FIG.  2    is a schematic block diagram of an example node/device  200  that may be used with one or more embodiments described herein, e.g., as any of the devices  102 - 106  shown in  FIG.  1    above. Device  200  may also be any other suitable type of device depending upon the type of network architecture in place, such as a collaboration endpoint, IoT nodes, etc. Device  200  comprises one or more network interface  210 , one or more audio interfaces  212 , one or more video interfaces  214 , one or more processors  220 , and a memory  240  interconnected by a system bus  250 , and is powered by a power supply  260 . 
     The network interfaces  210  include the mechanical, electrical, and signaling circuitry for communicating data over physical links coupled to the network(s)  110 . The network interfaces may be configured to transmit and/or receive data using a variety of different communication protocols. Note, further, that device  200  may have multiple types of network connections via interfaces  210 , e.g., wireless and wired/physical connections, and that the view herein is merely for illustration. 
     The audio interfaces  212  may include the mechanical, electrical, and signaling circuitry for transmitting and/or receiving audio signals to and from the physical area in which device  200  is located. For instance, audio interfaces  212  may include one or more speakers and associated circuitry to generate and transmit soundwaves. Similarly, audio interfaces  212  may include one or more microphones and associated circuitry to capture and process soundwaves. 
     The video interfaces  214  may include the mechanical, electrical, and signaling circuitry for displaying and/or capturing video signals. For instance, video interfaces  214  may include one or more display screens. At least one of the display screens may comprise a touch screen, such as a resistive touchscreen, a capacitive touchscreen, an optical touchscreen, or other form of touchscreen display, to allow a user to interact with device  200 . In addition, video interfaces  214  may include one or more cameras, allowing device  200  to capture video of a user for transmission to a remote device via network interfaces  210 . Such cameras may be mechanically controlled, in some instances, to allow for repositioning of the camera, automatically. 
     The memory  240  comprises a plurality of storage locations that are addressable by the processor(s)  220  and the network interfaces  210  for storing software programs and data structures associated with the embodiments described herein. The processor  220  may comprise hardware elements or hardware logic adapted to execute the software programs and manipulate the data structures  245 . An operating system  242 , portions of which are typically resident in memory  240  and executed by the processor, functionally organizes the device by, among other things, invoking operations in support of software processes and/or services executing on the device. These software processes and/or services may comprise a one or more functional processes  246 , and on certain devices, an illustrative videoconferencing process  248 , as described herein. Notably, functional processes  246 , when executed by processor(s)  220 , cause each particular device  200  to perform the various functions corresponding to the particular device&#39;s purpose and general configuration. For example, a router would be configured to operate as a router, a server would be configured to operate as a server, an access point (or gateway) would be configured to operate as an access point (or gateway), a client device would be configured to operate as a client device, and so on. 
     It will be apparent to those skilled in the art that other processor and memory types, including various computer-readable media, may be used to store and execute program instructions pertaining to the techniques described herein. Also, while the description illustrates various processes, it is expressly contemplated that various processes may be embodied as modules configured to operate in accordance with the techniques herein (e.g., according to the functionality of a similar process). Further, while the processes have been shown separately, those skilled in the art will appreciate that processes may be routines or modules within other processes. 
     During execution, videoconferencing process  248  may be configured to allow device  200  to participate in a virtual meeting (which may from time to time be referred as a videoconference) during which video data captured by video interfaces  214  and audio data captured by audio interfaces  212  is exchanged with other participating devices of the virtual meeting (or a videoconference) via network interfaces  210 . In addition, videoconferencing process  248  may provide audio data and/or video data captured by other participating devices to a user via audio interfaces  212  and/or video interfaces  214 , respectively. As would be appreciated, such an exchange of audio and/or video data may be facilitated by a videoconferencing service (e.g., Webex by Cisco Systems, Inc., etc.) that may be hosted in a data center, the cloud, or the like. 
       FIG.  3    illustrates an example meeting room  300  in which a collaboration endpoint  302  is located, according to various embodiments. During operation, collaboration endpoint  302  may capture video via its one or more cameras  308 , audio via one or more microphones, and provide the captured audio and video to any number of remote locations (e.g., other collaboration endpoints) via a network. Such videoconferencing may be achieved via a videoconferencing/management service located in a particular data center or the cloud, which serves to broker connectivity between collaboration endpoint  302  and the other endpoints for a given meeting. For instance, the service may mix audio captured from different endpoints, video captured from different endpoints, etc., into a finalized set of audio and video data for presentation to the participants of a virtual meeting (or a videoconference). Accordingly, collaboration endpoint  302  may also include a display  304  and/or speakers  306 , to present such data to any virtual meeting (or a videoconference) participants located in meeting room  300 . 
     Also as shown, a control display  310  may also be installed in meeting room  300  that allows a user to provide control commands for collaboration endpoint  302 . For instance, control display  310  may be a touch screen display that allows a user to start a virtual meeting, make configuration changes for the videoconference or collaboration endpoint  302  (e.g., enabling or disabling a mute option, adjusting the volume, etc.) 
     In some cases, any of the functionalities of collaboration endpoint  302 , such as capturing audio and video for a virtual meeting (or a videoconference), communicating with a videoconferencing service, presenting videoconference data to a virtual meeting participant, etc., may be performed by other devices, as well. For instance, a personal device such as a laptop computer, desktop computer, mobile phone, tablet, or the like, may be configured to function as an endpoint for a videoconference (e.g., through execution of a videoconferencing client application), in a manner similar to that of collaboration endpoint  302 . 
       FIG.  4    illustrates an example display of a virtual meeting (or a videoconference)  400 , according to various embodiments. As shown, video for participants  402  may be presented in conjunction with that of a presenter  404 . For instance, video data for each of participants  402  (e.g., video captured by each of their respective cameras) may be presented along the bottom of the displayed conference, along a side of the displayed conference, or the like. Typically, the host or presenter of the videoconference, may be displayed in a prominent location on screen, with their video appearing much larger than that of participants  402 . This may be considered a stage or presenter mode of the virtual meeting. However, other presentation modes are contemplated, for instance, where each participant shares an equal amount of the displayed conference. Participants of a videoconference typically have limited control over their video streams during a virtual meeting, which can create additional overhead for the system. For instance, the videoconferencing service may allow participants  402  and/or presenter  404  to apply a masking to their video feeds, to replace their physical backgrounds with different images (e.g., a participant working from home may instead appear to the other participants as being located on the beach). 
     —Audio Manipulation for Virtual Backgrounds— 
     As noted above, virtual meetings, by leveraging videoconference technologies, have become increasingly used, particularly due to remote work environments, as well as for non-work settings (e.g., classrooms, families, friends, etc.). To participate in virtual meetings, participants may be able to join by executing a corresponding application on their personal devices, such as computers, mobile phones, or the like. In addition, collaboration equipment, such as videoconferencing equipment found in meeting rooms, kiosks, and the like are becoming increasing ubiquitous in many settings. 
     Videoconference technologies have allowed participants to apply a virtual background (e.g., a masking) to their video feeds, to replace their physical backgrounds with different images (e.g., a participant working from home may instead appear to the other participants as being located on the beach). Virtual meeting participants, by using virtual backgrounds, have been able to disguise their physical backgrounds with varying levels of success. Participants, recently, have also started using virtual backgrounds to express themselves by selecting images that match their personalities, reflect their moods, etc. These virtual backgrounds, due to solely being based on one of the five senses, vision, are limited in the amount of immersion and customization they are able to provide. That is, in cases of a participants attempting to, using virtual backgrounds, either to disguise their physical backgrounds or to express themselves, videoconference technologies have been developed with a focus only on the visual aspect of virtual backgrounds. 
     The techniques herein, therefore, enable automatic manipulation of an audio stream of a virtual meeting participant based on the participant&#39;s selection of a particular virtual background, in addition to applying the virtual background to a video stream of the participant. In particular, machine learning techniques may be leveraged to map any virtual background (that is selected by a participant) to sound files, audio enhancements/modifications, etc. that may enhance how the participant is perceived in the virtual meeting by other participants (when using the virtual background). In an example, the participant may select a virtual background of a fish aquarium, and a videoconference service, as described in greater detail herein, may, using machine learning, identify a visual context of the virtual background and then audio enhancements that are associated with the visual context. The participant, when participating in the virtual meeting with the virtual background, may then be presented with his or her audio being modified with the audio enhancements (in addition to the virtual background). In the example of the fish aquarium virtual background, for instance, bubble sounds (e.g., audio clips) may be added to the participant&#39;s audio stream and/or the participant&#39;s voice may be augmented such that it appears that the participant is under water. 
     It is contemplated that a level of the modification of the participant&#39;s audio stream may need to be modulated, taking into account the participant&#39;s and other participants&#39; desires. In one or more embodiments, various toggles may be provided by the videoconference service such that modifications to an audio stream of a participant may be end user configured. Further, rotating virtual backgrounds and/or animated virtual backgrounds are contemplated, such that modifications to a participant&#39; audio stream can take into account objects located within the virtual backgrounds. In addition, differing modes of a virtual meeting, for example, a (shared) themed meeting, a stage (or presenter) mode, a waiting room/lobby mode, etc., are contemplated such that modifications to one or more participants&#39; audio streams are correspondingly applied. 
     Specifically, according to one or more embodiments described herein, a videoconference service determines a selection of a virtual background for a videoconference from a particular participant of a plurality of participants in the videoconference. The videoconference service determines an audio context filter that is associated with a visual context of the virtual background. The videoconference service modifies an audio stream of the videoconference into a modified audio stream according to the audio context filter. The videoconference service presents, to the plurality of participants during the videoconference, the particular participant using the virtual background and the modified audio stream. In an embodiment, the videoconference service ascertains the visual context of the virtual background based on applying a machine learning model to the virtual background. 
     Notably, the techniques herein may employ any number of machine learning techniques, such as to classify one or more virtual backgrounds, visual contexts (associated with the virtual backgrounds), and/or audio context filters (associated with the virtual backgrounds) and to cluster the data as described herein. In general, machine learning is concerned with the design and the development of techniques that receive empirical data as input (e.g., collected metric/event data from agents, sensors, etc.) and recognize complex patterns in the input data. For example, some machine learning techniques use an underlying model M, whose parameters are optimized for minimizing the cost function associated to M, given the input data. For instance, in the context of classification, the model M may be a straight line that separates the data into two classes (e.g., labels) such that M=a*x+b*y+c and the cost function is a function of the number of misclassified points. The learning process then operates by adjusting the parameters a, b, c such that the number of misclassified points is minimal. After this optimization/learning phase, the techniques herein can use the model M to classify new data points. Often, M is a statistical model, and the cost function is inversely proportional to the likelihood of M, given the input data. 
     One class of machine learning techniques that is of particular use herein is clustering. Generally speaking, clustering is a family of techniques that seek to group data according to some typically predefined or otherwise determined notion of similarity. 
     Also, the performance of a machine learning model can be evaluated in a number of ways based on the number of true positives, false positives, true negatives, and/or false negatives of the model. 
     In various embodiments, such techniques may employ one or more supervised, unsupervised, or semi-supervised machine learning models. Generally, supervised learning entails the use of a training set of data, as noted above, that is used to train the model to apply labels to the input data. On the other end of the spectrum are unsupervised techniques that do not require a training set of labels. Notably, while a supervised learning model may look for previously seen patterns that have been labeled as such, an unsupervised model may attempt to analyze the data without applying a label to it. Semi-supervised learning models take a middle ground approach that uses a greatly reduced set of labeled training data. 
     Example machine learning techniques that the techniques herein can employ may include, but are not limited to, nearest neighbor (NN) techniques (e.g., k-NN models, replicator NN models, etc.), statistical techniques (e.g., Bayesian networks, etc.), clustering techniques (e.g., k-means, mean-shift, etc.), neural networks (e.g., reservoir networks, artificial neural networks, etc.), support vector machines (SVMs), logistic or other regression, Markov models or chains, principal component analysis (PCA) (e.g., for linear models), multi-layer perceptron (MLP) artificial neural networks (ANNs) (e.g., for non-linear models), replicating reservoir networks (e.g., for non-linear models, typically for time series), random forest classification, or the like. 
     Operationally,  FIGS.  5 A-C  illustrate an example architecture  500  for machine learning-based audio manipulation using virtual backgrounds for virtual meetings, according to various embodiments. At the core of architecture  500  is videoconferencing process  248 , which may be executed by a device that provides a videoconferencing (or virtual meeting) service in a network, or another device in communication therewith. Additionally, as shown, architecture  500  may include a first client  502  and a second client  504  that operate in conjunction with one another and videoconferencing process  248 , to form a video conference system. 
     For purposes of illustration, assume that client  502  and client  504  are operated by participants (e.g., end users) of virtual meeting. Each of client  502  and client  504  may generate and send audio-video streams  506 ,  508  to videoconferencing process  248 , where audio-video streams  506 ,  508  include video captured by a corresponding camera of the clients (e.g., a video of the participant) as well as audio captured by a corresponding microphone of the clients (e.g., a sound recording of the participant). Subsequent to receiving audio-video streams  506 ,  508 , videoconferencing process  248  may be configured to generate and send conference streams  510 ,  512  to, respectively, client  502  and client  504 , where conference streams  510 ,  512  may be used by the clients to display a virtual meeting (or a videoconference), for example, as described with respect to  FIG.  4   . It is to be understood that participants at client  502  or client  504  may indicate a selection of a virtual background (e.g., an image file, a context for an image that can be automatically selected, etc.) to be applied to a participant&#39;s video of, for example, audio-video streams  506 ,  508 . Videoconferencing process  248  may, after receiving this selection, modify conference streams  510 ,  512  such that the participant&#39;s video includes the virtual background. Additionally, as will be described in greater detail herein, videoconferencing process  248  may also, based on the virtual background, manipulate the participant&#39;s audio based on the selected virtual background. 
     In particular, with reference now to  FIG.  5 B , more details regarding videoconferencing process  248  are shown. As shown, videoconferencing process  248  may include any or all of the following components: visual and audio content detection module  514 , one or more visual machine-learning based models  516 , one or more audio machine-learning based models  518 , and a visual and audio modification module  520 . As would be appreciated, the functionalities of these components may be combined or omitted, as desired. In addition, these components may be implemented on a singular device, for example, device  200 , or in a distributed manner, in which case the combination of executing devices can be viewed as their own singular device for purposes of executing videoconferencing process  248 . 
     As described above, videoconferencing process  248  may operate to receive audio-video streams  506  from client  502 , where audio-video stream  506  includes an indication  522  of a virtual background that has been selected by a participant at client  502  and an original audio stream  524  that includes audio recordings of the participant. In the example shown in  FIG.  5 B , the participant has selected a virtual background comprising an image of a sunken treasure ship, presumably deep under the ocean. Visual and audio content detection module  514  may be configured to receive indication  522  (of the image), or even the image file itself, and use it as input to one or more visual machine-learning based models  516  (e.g., a convolutional neural network (CNN) or one or more of the machine learning techniques described above) that have been trained to ascertain (or detect) a visual context of the image. Additionally, visual and audio content detection module  514  may be configured to apply one or more audio machine-learning based models  518  that are configured to map the ascertained visual context to one or more audio filters. The audio filters may comprise a plurality of sound files, a plurality of voice modifications (for the participant&#39;s voice), etc. that are related to the visual context and, by extension, the participant&#39;s selected visual background. 
     The audio filters may be understood as including both additions to original audio stream  524  as well as modifications to original audio stream  524  itself. According to one or particular embodiments herein, visual and audio modification module  520  may be configured to consider additions to the original audio stream  524  as background modifications to original audio stream  524  and modifications to original audio stream  524  as foreground modifications. In the example shown in  FIG.  5 B , an audio filter that has been mapped to the visual context associated with the image of the sunken treasure ship may include bubble sounds or clips (e.g., a background sound addition), a “muffling” filter that modifies a human voice such that the voice appears to be underwater (e.g., a foreground sound modification or enhancement), etc. Furthermore, background sound additions may be understood and categorized, for example, by one or more audio machine-learning based models  518 , as “static” or “dynamic” noise additions, where static noises are ones that may be persistently added whenever a participant (that has selected a virtual background) is talking (e.g., chirping bug noise(s), a murmur of a crowd, etc.), while “dynamic” noises are ones that may be tied to animated images, as will be described in greater detail herein below. 
     It is also contemplated that visual and audio modification module  520  may configured to apply the one or more audio filters in a variety of manners such that white noise mitigation, research, or best practices may be taken into account. Notably, contextual awareness may be applied so that background noise additions are only applied when there is no voice (e.g., of a participant) detected in original audio stream  524 . Alternatively, if a voice is detected in original audio stream  524  the background noise additions may be de-emphasized (or faded out) by visual and audio modification module  520 . Additionally, degrees/levels may separately be assigned to each of background noise additions and voice enhancements based on a participant&#39;s preference (that may be provided via a toggle at a client  502  or client  504 ). 
     Visual and audio modification module  520  may then apply the one or more audio filters to the original audio stream  524  to generate a modified audio stream  526 . Videoconferencing process  248  may then include modified audio stream  526  as part of conference stream  512 , which also includes the indication  522  of the participant&#39;s selected virtual background. Client  504  may receive conference stream  512  then present the participant from client  502  to be appear with the virtual background, as shown in the example display  528  of a virtual meeting. According to one or particular embodiments herein, client software at client  502  or client  504  may be configured to locally download the one or more audio filters (that have been mapped by visual and audio content detection module  514  to a visual context of a virtual background) from videoconferencing process  248 , and to apply the one or more audio filters on its own (instead of having visual and audio modification module  520  generate conference stream  512 ). 
     In one or more additional embodiments, visual and audio content detection module  514  may be configured to obtain feedback from participants (e.g., at client  502 ) of the virtual meeting regarding conference stream  512  (i.e., such feedback may be in the form of a survey, thumps up/down selections, etc. at the conclusion of the virtual meeting). Visual and audio content detection module  514  may then, based on the obtained feedback, train one or more of the visual machine-learning based models  516  or the audio machine-learning based models  518 . 
     Turning now to  FIGS.  6 A- 6 B , example virtual background images are shown. In particular,  FIG.  6 A  illustrates a virtual background image of a desert that may be selected by a participant of a virtual meeting. Visual and audio content detection module  514  may, using this image, be able to ascertain a visual context of this image that is mapped to a plurality of sounds that is associated with a desert image, for example, blowing sand, high winds, etc., which as described above may be considered background modifications (i.e., additions) to an audio stream of a participant. Some foreground modifications for desert-related audio context may comprise a faint-sounding filter, scratchy-voice filter, etc. Turning to  FIG.  6 B  illustrates a virtual background image of a jungle that may be selected by a participant of a virtual meeting. Visual and audio content detection module  514  may, using this image, be able to ascertain a visual context of this image that is mapped to a plurality of sounds that is associated with a jungle image, including animal sounds, bug noises, etc. 
     In one or more additional embodiments, it is contemplated that a virtual background selected by a participant of a virtual meeting may be more than a static image file and may, instead, include an animated image file (e.g., a .gif). Alternatively, it is contemplated that visual and audio content detection module  514  may be configured to identify objects, shapes, etc. that are commonly associated with a visual context associated with a virtual background by a participant, and to insert one or more of these objects into a virtual background. For example, in  FIG.  7   , an example rotating virtual background is shown that comprises two images, image  702  of an underground setting and image  704  of the underground setting with a diver. Visual and audio modification module  520  may be able to either determine both of these images from an animated image file received from a client (e.g., client  502 ) or to modify or alter a participant&#39;s virtual background (from image  700  to image  702  or from image  702  to image  700 ) to create this rotating virtual background. Visual and audio modification module  520  may, based on these images  700 ,  702 , be configured to dynamically modify original audio stream  524  such that additions of sound files (e.g., a bubble sound) are only added when objects are detected in the rotating virtual background (for example, when the diver shown in image  702  appears). Voice enhancements (e.g., foreground sound modifications to original audio stream  524 ) may be applied by visual and audio modification module  520  in each of image  700  and image  702  or, in other embodiments, only when image  700  appears. 
     In one or more additional embodiments, visual and audio content detection module  514  in combination with visual and audio modification module  520  may additionally add a spatial element to modification to original audio stream  524 . In  FIG.  8   , an example animated virtual background is shown that comprises image  800 , image  802 , and image  804 . Each of the images includes a desert background, but image  800  at time=0 includes an object (as shown, an airplane) on the left side of the virtual background, image  802  at time=0+1 includes the object in a central portion of the virtual background, and image  804  at time=0+2 includes the object in the right side of the virtual background. Visual and audio content detection module  514  may be configured to detect locations of the object as it “moves” through the virtual background, and visual and audio content detection module  514 , based on the objects location, may modify original audio stream  524  such that sound associated with the object are only inserted into a corresponding channel (e.g., left of right) of modified audio stream  526 . 
     Returning to  FIG.  5 C , example display  528  is of a participant&#39;s perspective at client  504 , where another participant at client  502  has selected a particular virtual background. In particular, it is contemplated that videoconferencing process  248  may be configured to provide a themed meeting mode option (in addition to a stage (or presenter) mode), where after the selection of a particular virtual background by a participant is applied to one or more other participants  530  of the virtual meeting. In such themed meeting mode, videoconferencing process  248  may equally apply audio modifications to audio streams of each participant, such that each participant would hear the same exact sounds and the background noise would be congruent from a user perspective. For instance, a submarine may appear in the virtual background of a single participant, but an audio clip addition (to conference streams of the all the participants) may be applied for all members of the virtual meeting. It is contemplated, in an example, that if a presenter changes a different participant (of one or more other participants  53 ) that has a different virtual background, videoconferencing process  248  may be configured to smoothly transition all of the participants to the different virtual background as well as corresponding audio stream modifications/enhancements as described herein. 
     In one or more additional embodiments, a separate multi-user mode option may be provided by videoconferencing process  248 , where the videoconferencing process  248  may detect when a particular participant is active in a virtual meeting and only apply audio modifications when the participant is active, where the modifications are presented to each participant in the virtual meeting. For example, as shown in  FIG.  9    an example virtual meeting multi-user mode  900  is shown. The virtual meeting includes a first participant  902  who has selected a particular virtual background  904  and a second participant  906  who has selected another virtual background  908 . Additionally, an indicator  910  indicates that first participant  902  is actively speaking, and videoconferencing process  248  may be configured to detect the speech of first participant  902  and to apply audio stream modifications to an audio stream associated with first participant  902 , according to the techniques described herein above. 
     In one or more additional embodiments, it is contemplated that videoconferencing process  248  may be configured to only apply audio modifications based on a selected virtual background when no other participants are present in a virtual meeting. This may lobby mode of the virtual meeting, where the participant waits for participation by other members of the virtual meeting. In such a mode, the modifications to the audio stream of the participant may be heard in the participant&#39;s own stream, so that they may adjust or test out the sound. Alternatively, videoconferencing process  248  may be configured to apply audio modifications in a separate waiting area (or room), for example, prior to a virtual meeting starting and modify a participant&#39;s own audio stream such that the participant itself may have its own audio stream modified with additions associated with a self-selected virtual background. Furthermore, it is contemplated that videoconferencing process  248  may be configured to present a variety of toggles within displays of virtual meetings to enable participants to: disable audio stream modifications, entirely or in part; adjust the degree to which various types of audio stream additions and/or modifications are applied (e.g., how intense they are); etc. 
     In closing,  FIG.  10    illustrates an example simplified procedure for machine learning-based audio manipulation using virtual backgrounds for virtual meetings in accordance with one or more embodiments described herein, particularly from the perspective of a teleconference provider server or local end user/participant device, depending upon implementation. For example, a non-generic, specifically configured device (e.g., device  200 ) may perform procedure  1000  by executing stored instructions (e.g., process  248 ). The procedure  1000  may start at step  1005 , and continues to step  1010 , where, as described in greater detail above, a videoconference service may determine a selection of a virtual background for a videoconference from a particular participant of a plurality of participants in the videoconference. In an embodiment, videoconference service may apply the selection of the virtual background for the videoconference from the particular participant to the plurality of participants. In one particular embodiment, the virtual background may comprise an animated image file. In an embodiment, the videoconference service may be located within a cloud service or on endpoint devices of the plurality of participants. 
     At step  1015 , the videoconference service may determine an audio context filter that is associated with a visual context of the virtual background. In an embodiment, the videoconference service ascertains the visual context of the virtual background based on applying a machine learning model to the virtual background. In particular, the videoconference service may apply the virtual background one or more visual machine-learning based models (e.g., a convolutional neural network (CNN) or one or more of the machine learning techniques described above) that have been trained to ascertain (or detect) a visual context of the image. Additionally, the videoconference service may be configured to apply one or more audio machine-learning based models that are configured to map the ascertained visual context to one or more audio filters. 
     At step  1020 , the videoconference service may modify an audio stream of the videoconference into a modified audio stream according to the audio context filter. In an embodiment, modifying the audio stream of the videoconference into the modified audio stream according to the audio context filter may comprises adding, by the videoconference service, one or more audio clips associated with the audio context filter to the audio stream. In a further embodiment, adding the one or more audio clips may be based on whether an object is detected within the virtual background. In one particular embodiment, modifying the audio stream of the videoconference into the modified audio stream according to the audio context filter may comprise augmenting, by the videoconference service, a voice portion of the audio stream with a voice modification associated with the audio context filter. 
     At step  1025 , the videoconference service may present, to the plurality of participants during the videoconference, the particular participant using the virtual background and the modified audio stream. In an embodiment, presenting, to the plurality of participants during the videoconference, the particular participant using the virtual background and the modified audio stream may be based on whether the videoconference service has detected that the particular participant is speaking. In one particular embodiment, the videoconference service may present a toggle to each of the plurality of participants that allows a corresponding participant to disable the modified audio stream. In another embodiment, the videoconference service may present a toggle to each of the plurality of participants that allows a corresponding participant to select whether static audio clips or dynamic audio clips are added to the audio stream 
     The simplified procedure  1000  may then end in step  1030 , notably with the ability to continue ingesting and clustering data. Other steps may also be included generally within procedure  1000 . For example, such steps (or, more generally, such additions to steps already specifically illustrated above), may include: ascertaining, by the videoconference service, the visual context of the virtual background based on applying a machine learning model to the virtual background; obtaining, by the videoconference service and from the plurality of participants, feedback regarding the virtual background and the modified audio stream; and training, by the videoconference service, the machine learning model based on the feedback; and so on. 
     It should be noted that while certain steps within procedure  1000  may be optional as described above, the steps shown in  FIG.  10    are merely examples for illustration, and certain other steps may be included or excluded as desired. Further, while a particular order of the steps is shown, this ordering is merely illustrative, and any suitable arrangement of the steps may be utilized without departing from the scope of the embodiments herein. 
     The techniques described herein, therefore, provide for machine learning-based audio manipulation using virtual backgrounds for virtual meetings. In particular, the techniques herein, in addition to applying the virtual background to a video stream of the participant, leverage machine learning techniques to automatically detect one or more audio enhancements that may be applied to an audio stream associated with a participant, based on a virtual background selected the participant. The participant may then be presented with his or her audio being modified with the audio enhancements (in addition to the virtual background). Further, the techniques herein may be configured to detect objects within a virtual background, and accordingly modify the audio stream based on the presence of the objects, for example, for when animated image files are used as virtual backgrounds. In addition, the techniques herein may be configured in a manner that corresponds to different modes of a virtual meeting (e.g., a lobby mode, a themed meeting, or a stage mode). 
     Illustratively, the techniques described herein may be performed by hardware, software, and/or firmware, such as in accordance with the illustrative videoconferencing process  248 , which may include computer executable instructions executed by the processor  220  to perform functions relating to the techniques described herein, e.g., in conjunction with corresponding processes of other devices in the computer network as described herein (e.g., on computing devices, servers, etc.). In addition, the components herein may be implemented on a singular device or in a distributed manner, in which case the combination of executing devices can be viewed as their own singular “device” for purposes of executing the process  248 . 
     According to the embodiments herein, an illustrative method herein may comprise: determining, by a videoconference service, a selection of a virtual background for a videoconference from a particular participant of a plurality of participants in the videoconference; determining, by the videoconference service, an audio context filter that is associated with a visual context of the virtual background; modifying, by the videoconference service, an audio stream of the videoconference into a modified audio stream according to the audio context filter; and presenting, by the videoconference service and to the plurality of participants during the videoconference, the particular participant using the virtual background and the modified audio stream. 
     In one embodiment, modifying the audio stream of the videoconference into the modified audio stream according to the audio context filter comprises: adding, by the videoconference service, one or more audio clips associated with the audio context filter to the audio stream. In one embodiment, adding the one or more audio clips is based on whether an object is detected within the virtual background. In one embodiment, modifying the audio stream of the videoconference into the modified audio stream according to the audio context filter comprises: augmenting, by the videoconference service, a voice portion of the audio stream with a voice modification associated with the audio context filter. In one embodiment, presenting, by the videoconference service and to the plurality of participants during the videoconference, the particular participant using the virtual background and the modified audio stream is based on whether the videoconference service has detected that the particular participant is speaking. In one embodiment, the videoconference service applies the selection of the virtual background for the videoconference from the particular participant to the plurality of participants. In one embodiment, the virtual background comprises an animated image file. In one embodiment, the videoconference service presents a toggle to each of the plurality of participants that allows a corresponding participant to disable the modified audio stream. In one embodiment, the videoconference service presents a toggle to each of the plurality of participants that allows a corresponding participant to select whether static audio clips or dynamic audio clips are added to the audio stream. In one embodiment, the videoconference service is located within a cloud service or on endpoint devices of the plurality of participants. In one embodiment, the illustrative method herein may further comprise ascertaining, by the videoconference service, the visual context of the virtual background based on applying a machine learning model to the virtual background. In one embodiment, the illustrative method herein may further comprise: obtaining, by the videoconference service and from the plurality of participants, feedback regarding the virtual background and the modified audio stream; and training, by the videoconference service, the machine learning model based on the feedback. 
     According to the embodiments herein, an illustrative tangible, non-transitory, computer-readable medium herein may have computer-executable instructions stored thereon that, when executed by a processor on a computer, may cause the computer to perform a method comprising: determining a selection of a virtual background for a videoconference from a particular participant of a plurality of participants in the videoconference; determining an audio context filter that is associated with a visual context of the virtual background; modifying an audio stream of the videoconference into a modified audio stream according to the audio context filter; and presenting, to the plurality of participants during the videoconference, the particular participant using the virtual background and the modified audio stream. 
     Further, according to the embodiments herein an illustrative apparatus herein may comprise: one or more network interfaces to communicate with a network; a processor coupled to the network interfaces and configured to execute one or more processes; and a memory configured to store a process that is executable by the processor, the process, when executed, configured to: determine a selection of a virtual background for a videoconference from a particular participant of a plurality of participants in the videoconference; determine an audio context filter that is associated with a visual context of the virtual background; modify an audio stream of the videoconference into a modified audio stream according to the audio context filter; and present, to the plurality of participants during the videoconference, the particular participant using the virtual background and the modified audio stream. 
     While there have been shown and described illustrative embodiments above, it is to be understood that various other adaptations and modifications may be made within the scope of the embodiments herein. For example, while certain embodiments are described herein with respect to certain types of networks in particular, the techniques are not limited as such and may be used with any computer network, generally, in other embodiments. Moreover, while specific technologies, protocols, and associated devices have been shown, such as such as for videoconferencing services, other suitable technologies, protocols, and associated devices may be used in accordance with the techniques described above, such as one-on-one video communication protocols (e.g., video calls). In addition, while certain devices are shown, and with certain functionality being performed on certain devices, other suitable devices and process locations may be used, accordingly. That is, the embodiments have been shown and described herein with relation to specific network configurations (orientations, topologies, protocols, terminology, processing locations, etc.). However, the embodiments in their broader sense are not as limited, and may, in fact, be used with other types of networks, protocols, and configurations. 
     Moreover, while the present disclosure contains many other specifics, these should not be construed as limitations on the scope of any embodiment or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular embodiments. Certain features that are described in this document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Further, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination. 
     Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Moreover, the separation of various system components in the embodiments described in the present disclosure should not be understood as requiring such separation in all embodiments. 
     The foregoing description has been directed to specific embodiments. It will be apparent, however, that other variations and modifications may be made to the described embodiments, with the attainment of some or all of their advantages. For instance, it is expressly contemplated that the components and/or elements described herein can be implemented as software being stored on a tangible (non-transitory) computer-readable medium (e.g., disks/CDs/RAM/EEPROM/etc.) having program instructions executing on a computer, hardware, firmware, or a combination thereof. Accordingly, this description is to be taken only by way of example and not to otherwise limit the scope of the embodiments herein. Therefore, it is the object of the appended claims to cover all such variations and modifications as come within the true intent and scope of the embodiments herein.