Abstract:
The electronic audio connection system of the present invention provides an experience much like sharing a room with several involved parties, even though the parties are physically separated. Speech enhancement and speech emphasis processing functions ensure parties perceive the speech captured in the audio signals, typically the most important portion of the captured audio signals. To capture audio signals, each space is provided a plurality of microphones arranged in that space so that the sum audio signal captured by the microphones enables the creation of a sharable audio space. Each separate physical space transmits its captured audio signals to a central server via a bi-directional data communications medium. The central server processes the summed audio signals and in turn transmits playable audio signals to each separate physical space. Speakers located in each separate physical space aurally transmit the playable audio signals. This creates an audio space shared by each of the active separate physical spaces.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This Application is related to and claims priority of U.S. Provisional Patent Application No. 60/062,144 filed Oct. 9, 1997, incorporated herein by reference. This Application is also related to and claims priority of U.S. Provisional Patent Application No. 60/103,814 entitled METHODS AND APPARATUS FOR REMOTE SOCIAL INTERACTIONS filed Oct. 8, 1998, incorporated herein by reference. This Application is also related to U.S. patent application Ser. Nos. (a) 08/610,638 filed Mar. 4, 1996, (b) entitled METHOD AND APPARATUS FOR SENDING AND RECEIVING LIGHTWEIGHT MESSAGES filed Oct. 9, 1998, (c) entitled METHOD AND APPARATUS FOR SENDING PRESENCE MESSAGES filed Oct. 9, 1998, and (d) entitled VARIABLE BANDWIDTH COMMUNICATION SYSTEMS AND METHODS filed Oct. 9, 1998, all four being incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to personal communication systems, and more particularly to electronic audio connection systems that enable two or more geographically separated physical spaces to interact socially within a shared audio space. 
     2. Description of the Related Art 
     Social reasons are the primary motivation for both intra-household (room to room) and inter-household (house to house) aural communication. For purposes of inter-household communication, households are primarily linked to one another by telephones and by telephone-extension devices such as answering machines. Related technologies include speaker-telephones. For purposes of intra-household communication, baby monitors enable parents to eavesdrop on their resting children from another room and intercoms enable people to talk room-to-room. 
     Ongoing contact with significant others is a fundamental human need not fully met by current household technologies. First, there is no technological support for a household to have continuous background awareness of distant households that it cares about, in the way that it has some ongoing awareness of physically neighboring households (e.g., by noticing a car is in the driveway, a lighted window, or muffled sounds of a conversation). Such awareness would allow conversations to take place opportunistically that currently do not take place, and might allow certain currently unwanted conversations to be avoided if such background awareness was sufficient for feeling “in touch.” 
     The telephone (currently the primary technological support for remote conversations) embodies a model for initiating and disengaging from social interaction that is rarely found in everyday life. Disregarding for the moment non-basic elements such as busy signals, answering machines, caller-ID, etc., the telephone provides three states: disconnected, ringing, and connected. The model of social interaction created is akin to that created by a windowless room with a closed, locked, and soundproof door. Callers are forced to initiate interaction by knocking (ringing), without any advance indication of the callee&#39;s situation within. 
     Similarly, the callee is forced to decide whether to unlock and open the door with very limited information (even more limited in the telephone case, as at least a knock can have a distinctive rhythm). Once unlocked and thrown open, the conversational partners confront each other at close range, with little ability to adjust social distance to a mutually desired level. Conversations end, with little subtlety or room for re-engagement, by shutting the door and returning to an entirely disengaged state. People have adapted to this model remarkably well, but a technology that offers a more flexible mutually negotiated approach would be highly desirable. 
     There are, of course, a number of conversational devices currently available for remote social interactions including telephones, videophones, online “chat” and audio/video-conferencing systems, and caller-ID devices. However, the production of high-tech communication devices for the home is an emerging field. For example, there has been some research moving away from PC-based applications towards small dedicated appliances designed to fit functionally and aesthetically into the home that can provide some form of remote social interaction. 
     The term “media space” refers to the linking of a number of physically separated spaces to create a larger “virtual space” for communication between various individuals. Researchers have noticed that it is very difficult to document an objective gain from use of media spaces in workplaces, but also that the users nevertheless were unanimous about the usefulness of these systems 
     A stated advantage is the social awareness that is provided and which may be conducive to deciding when direct communication would be appropriate. The awareness issue is sometimes refereed to as the support for background communication, see for instance William Buxton&#39;s GI (Graphical Interface) &#39;95-paper about foreground and background. 
     SUMMARY OF THE INVENTION 
     The present invention comprises a number of solutions for the aforementioned problems, which characteristically take the form of easy-to-use household communication appliances. These “appliances” are fairly termed electronic audio connection systems, for they enable geographically separate physical spaces to share a single audio space. The appliances of the present invention are meant to complement existing household technologies (e.g. personal computers or PCs), rather than to replace them. They are primarily conceived of as being stand-alone appliances to best fit their form to their function, and to appeal to consumers who do not have or want PCs, but at least some could be sold in an alternative version as a software application. 
     More particularly, the present invention comprises a set of easy-to-use consumer devices for lightweight social awareness and/or conversation between households of friends or family members or similar applications. The family of devices/capabilities (and related services) that the present invention contemplates focus on both home-to-home and room-to-room social communication range. This aural communication may be supplemented through simple feedback devices, buttons and timing circuitry that aid in the negotiation surrounding the sharing of an audio space. Lightweight, ephemeral connections and communication characterize them with friends and family. The devices of the present invention are less intrusive and simpler than a telephone, hands-free and high quality, yet more intimate and immediate than email. 
     Appropriately configured, an electronic audio connection system of the present invention conveys the experience of sharing a room with several involved parties. Speech enhancement and speech emphasis processing functions ensure parties perceive the speech captured in the audio signals, typically the most important portion of the captured audio signals. To capture audio signals, each space is provided a plurality of microphones arranged in that space so that the sum audio signal captured by the microphones enables the creation of a sharable audio space. Each separate physical space transmits its captured audio signals to a central server via a bi-directional data communications medium. The central server processes the summed audio signals and in turn transmits playable audio signals to each separate physical space. Speakers located in each separate physical space aurally transmit the playable audio signals. This creates an audio space shared by each of the active separate physical spaces. 
    
    
     These and other advantages of the present invention will become apparent upon reading the following detailed descriptions and studying the various figures of the drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings. To facilitate this description, like reference numerals designate like structural elements. 
     FIG. 1 diagrams an electronic audio connection system having a central server in accordance with one embodiment of the present invention. 
     FIG. 2 diagrams an electronic audio connection system incorporating standard telephone technology into the shared audio space of the present invention. 
     FIG. 3 diagrams an electronic audio connection system that establishes bi-directional communication between physical spaces and the central server over a single bus-like communications medium. 
     FIG. 4 diagrams an electronic audio connection system having a distributed virtual server in accordance with another embodiment of the present invention. 
     FIG. 5 diagrams an electronic audio connection system having multiple data communications mediums coupling the physical spaces and the central server. 
     FIG. 6 is an illustration of a control panel in accordance with one embodiment of the present invention. 
     FIG. 7 is a flow chart of a method for initiating the negotiation for the sharing of an audio space according to one aspect of the present invention. 
     FIG. 8 is a flow chart of a method for negotiating the sharing of an audio space according to another aspect of the present invention. 
     FIG. 9 is a flow chart of a calibration method according to still another aspect of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The electronic audio connection systems of the present invention are intended to be high quality, hands-free audio systems that enable geographically separate physical spaces to share a single audio space. The sharing of the audio space is typically prefaced by a negotiation between parties in the different spaces, ensuring voluntary and proactive involvement in the sharing. Several different audio connection systems of the present invention are described below with reference to FIGS. 1-5. 
     FIG. 1 diagrams an electronic audio connection system  100  in accordance with one embodiment of the present invention. The electronic audio connection system  100  includes a plurality of room-like, geographically separate physical spaces  102  each bi-directionally coupled to a central server  104  through a communications medium  106 . The particular physical space ROOM- 1  includes a plurality of speakers  110 , a plurality of microphones  112 , a control panel  114 , and an audio system base  116 . It is contemplated that these devices may be provided to the user in a compact, easily installable package. 
     The plurality of microphones  112  are arranged around the space ROOM- 1  in a manner suitable for capturing the audio space formed within ROOM- 1 . Similarly, the plurality of speakers  110  are arranged around ROOM- 1  in a manner suitable for creating and controlling the audio space of ROOM- 1  in a desired manner. Note that any constraint on possible speaker and microphone arrangements is due to digital signal processing (DSP) limitations. Thus, in theory, the devices could be placed in any arrangement as long as the necessary DSP functions are available to achieve the desired results. In preferred embodiments, the speakers  110  and the microphones  112  are unobtrusively positioned to become like part of the room. Locating the devices on the ceiling and hiding them in furniture, appliances, and the like are proposed. 
     Basic operation of the electronic audio connection system  100  is as follows. First there is a period of negotiation between the active physical spaces to determine issues such as which physical spaces  102  will be mixed into the shared audio space, how such shared audio space is formed, and what is the nature of the shared audio space. Possible negotiation processes are described below in more detail below with reference to FIGS. 6-8. Following the negotiation period, audio signals captured by the microphones  112  are transmitted to the audio system base  116 . Upon receipt of the captured audio signals, the base  116  may perform certain audio signal processing functions and then immediately transmit the processed audio signals to the central server  104  via the communications medium  106 . The central server  104  further processes the captured audio signals. Processing performed by the central server  104  typically includes mixing or filtered mixing of the various received audio signals. The central server  104  then transmits to each active physical space a meaningful set of audio signals. In turn, each active physical space uses its speakers  110  to aurally transmit the received set of audio signals. The audio signals transmitted to each active physical space are suitable to allow each active physical space to share, in a sense, a single audio space. For example, listeners present in a first active space can be provided an audio space full of aural signals originating from a geographically separate physical space. 
     FIGS. 2-5 diagram several different electronic audio connection systems of the present invention. The audio connection systems of these Figures each illustrate different aspects of the present invention. Nonetheless, in many ways each system operates like the audio connection system  100  of FIG.  1 . For brevity&#39;s sake, therefore, the following descriptions focus on the differences between the various example systems rather than describing similar features repetitively. 
     FIG. 2 diagrams a second electronic audio connection system  150  in accordance with another embodiment of the present invention. Like system  100 , the electronic audio connection system  150  couples multiple physical spaces  102  to a central server  104  via communications medium  106 . However, the electronic audio connection system  150  also incorporates a standard telephone  202  and a speaker telephone  204  into its operation by placing them in ROOM- 2  and ROOM- 3 , respectively. This simply means that the audio information made available by these devices can be included into the shared audio space generated by the central server  104 . Likewise, some form of the shared audio space can be provided to spaces ROOM- 2  and ROOM- 3  via the standard telephone  202  and the speaker telephone  204 . 
     Incorporation of standard telephone devices into the audio connection system  150  indicates not only the backwards compatible nature of the present invention, but also its inherent flexibility. In particular, since signal processing is an ongoing occurrence, any type of information can be added to the shared audio space. A certain user may desire to create aural signals without directly generating such signals. For example, a mute person may use a keyboard or other input device to translate input data into aural signals. These aural signals could be mixed into the shared audio space as the mute person&#39;s contribution. Along different lines, the shared audio space can be augmented by a virtual audio space. For example, the users may decide to mix into their shared audio space the sounds of a rain forest or a thronging crowd, depending upon the mood. 
     FIG. 3 diagrams yet another electronic audio connection system  200  in accordance with the present invention. In the electronic audio connection system  100  of FIG. 1, the data communications medium  106  was made up of several distinct bi-directional couplings between the physical spaces  102  and the central server  104 . Here with the electronic audio connection system  200  of FIG. 3, a bus-like data communications medium  206  is shared by each of the devices. The bus-like data communications medium  206  can be implemented over the Internet or other suitable network. 
     FIG. 4 diagrams still another electronic audio connection system  220  in accordance with the present invention. Within the electronic audio connection system  200 , the signal processing functions are distributed across the bases of the different rooms, creating a distributed or virtual server. Thus, unlike the earlier described electronic audio connection systems, the electronic audio connection system  220  does not have a central server  104 . This is an advantage because it requires one less computer system and distributes processing requirements across the entire system. 
     FIG. 5 diagrams yet another electronic audio connection system  240  in accordance with another embodiment of the present invention. The electronic audio connection system  240  includes additional transmission medium  242  that serves to couple each room with a central server  104 . For example, each room  102  may only be on-line when actively sharing an audio space and thus when not actively sharing, a room  102  may be out of touch with other users&#39; requests and communications. However, transmission medium  242 , which may be a paging system or such, may be used by the central server to activate or communicate with the desired room  102 . 
     FIG. 6 illustrates a control panel  114  in accordance with yet another embodiment of the present invention. For the purposes of the present discussion, assume the control panel  114  is found in a physical space ROOM- 1 . The control panel  114  includes several speed-link buttons  300 , a volume control  302 , a power control  304 , and a mute button  306 . Operations of the volume control  302 , power control  304 , and mute  306  buttons should be self-explanatory. 
     The speed-link buttons  300  of FIG. 6 are operable to request and accept connections to separate physical spaces  102 . For example, a user selecting the speed-link button  300  labeled “MOM” may initiate a negotiation period wherein the separate physical space  102  associated with “MOM” is queried as to whether sharing of an audio space is acceptable. When the separate physical space  102  acknowledges and accepts sharing, the central server  104  creates the desired audio space. On the flip side, the speed-link button  300  labeled “MOM” includes a feedback mechanism that indicates to a listener in ROOM- 1  whether sharing of an audio space associated with “MOM” is requested or even presently active. For example, a blinking “MOM” light might indicate that “MOM” wishes to establish a shared audio space with ROOM- 1 . Selecting the speed-link button  300  with the label “MOM” may establish such a shared audio space. Then the “MOM” light may glow continuously indicating an active shared audio space. 
     It will be appreciated that the electronic audio connection systems of the present invention are particularly well suited to voice controlled operation. The sophistication of such implementations could vary greatly. The voice controlled electronic audio connection system of the present invention could be responsive to specific voice commands, rendering the electronic audio connection system completely hands-free. For example, a user could enunciate a particular person&#39;s name, and the electronic audio connection system could respond by initiating negotiation for the sharing of an audio space with that person. Speaker identification processes enable a person to simply state “MOM” and the electronic audio connection system could identify the requester and thus identify and initiate negotiation with “MOM.” Power, mute, and volume functions could all be implemented through voice commands, creating an easy-to-use means for communicating with remote parties. 
     Speaker identification could also allow emphasis or de-emphasis of particular speakers. By way of example, when one party in a household wishes to maintain privacy, that party&#39;s voice could be filtered out or at least de-emphasized. Alternatively, a party from one room may only wish to engage in sharing with a particular person in a particular room. Speaker identification would enable such a negotiation to take place. 
     Beyond detecting the speaker&#39;s identity, aural signal processing functions can be implemented to ascertain affect of sensed speech. That is, the emotive state of the speaker as represented by his or her speech can be determined and utilized for filtering purposes. For example, a devoted son may program the electronic audio connection system such that a distressed communication from his mother would immediately open the connection, skipping the negotiation process and emphasizing his mother&#39;s words. Alternatively, stressful but private situations (e.g., a couple fighting) could be sensed and the private dialogue filtered out. For more information on recognition systems for affective vocalizations, please see Slaney and McRoberts&#39; article entitled “BABY EARS: A RECOGNITION SYSTEM FOR AFFECTIVE VOCALIZATION” published in the  Proceedings of the  1998  International Conference on Acoustics, Speech, and Signal Processing  ( ICASSP ), Seattle, Wash., May 12-15, 1998. 
     FIG. 7 is a flow chart illustrating a method  400  for negotiating within an electronic audio connection system the formation of a shared audio space. The method  400  would be suitable for use with the electronic audio connection systems  100  and  200  of FIGS. 1 and 2, respectively. Similarly, the control panel  114  of FIG.  6  and the above described voice control system would be suitable for operation with the method  400  of FIG.  7 . 
     The method  400  begins in a start step  402 . The start step  402  may include any necessary initiation processes required to accomplish the formation of a shared audio space. For example, the calibration method  700  of FIG. 9 described below may be performed as part of the start step  402 . However, in preferred embodiments calibration is performed only as necessary, not during each startup period. Once properly initiated in the start step  402 , control of the method passes to a step  404 . The step  404  corresponds to ROOM- 1  initiating negotiation by requesting that an electronic audio connection be established with a ROOM- 2 . The negotiation initiation step  404  may arise in a variety of ways. For instance, a listener in ROOM- 1  may select a speed-link button on a control panel  114  found in ROOM- 1 . Alternatively, the control panel  114  or the base  116  may be programmed to initiate negotiation based upon some particular event. For instance, a listener may program the control panel to negotiate a connection with ROOM- 2  every day at 12:00 PM. In any event, once negotiation has been initiated in the step  404 , control of the method  400  passes to a determination step  406 . Step  406  determines whether ROOM- 2  has indicated whether it accepts the desired electronic audio connection shared audio space. If ROOM- 2  does not indicate that it accepts sharing of an audio space, in a step  408  the method  400  determines whether the request is cancelled. Note that in preferred embodiments, both ROOM- 1  and ROOM- 2  can cancel the request. When the step  406  determines that ROOM- 2  accepts sharing of a single audio space, a step  410  establishes the electronic audio connection. 
     FIG. 8 is a flow chart illustrating a method  500  for responding to a negotiation initiation such as method  400  of FIG.  7 . As with the method  400 , the method  500  would be suitable for use with the electronic audio connection systems  100  and  200  of FIGS. 1 and 2, respectively. Similarly, the control panel  114  of FIG.  6  and the above described voice control system would be suitable for operation with the method  500  of FIG.  8 . 
     The method  500  begins in a start step  502 . The start step  502  may include any necessary initiation processes required to accomplish the formation of a shared audio space. For example, the calibration method  600  of FIG. 9 described below may be performed as part of the start step  502 . Once properly initiated in the start step  502 , control of the method passes to a step  504  wherein ROOM- 2  receives a request to establish an electronic audio connection with ROOM- 1 . In response, in a step  506  the ROOM- 2  control panel  114  provides feedback indicating the existence of the request initiated by ROOM- 2 . As mentioned above, this may include a flashing light, an audible sound, or some other appropriate indication. 
     In a next step  508 , it is determined whether ROOM- 2  has accepted the ROOM- 1  request. If not, in a step  510  it is determined whether ROOM- 2  has cancelled the ROOM- 1  request. As mentioned above, in certain embodiments both ROOM- 1  and ROOM- 2  may cancel the request. If the request for a shared audio space is canceled, then the method  500  is completed in a final step  512 . The final step  512  may involve shutdown procedures such as keeping statistical track of communications links requested and not established. 
     If in the step  508  it is determined that ROOM- 2  accepts the requested shared audio space, in a step  514  it is determined whether the request is still active (for example, ROOM- 1  may have cancelled the request in the intervening time period). When the request is not active, control is passed to the final step  512 . However, when the request is active and ROOM- 2  accepts, a step  516  establishes the electronic audio connection thereby enabling sharing of a single audio space. 
     During the course of implementing the electronic audio connection systems of the present invention, the inventors determined several challenges arising from the inherent nature of these systems. Namely, issues such as latency, unwanted echo, unwanted reverberation, and unique requirements for audio filtration naturally arose. Echo and reverb cancellation can be accomplished through standard techniques known to those skilled in the art. The other two issues raised more irksome dilemmas. 
     Latency (i.e., the time required for the desired audio signals to be available after processing and transmission delays are factored in) can be minimized by sheer brute force. That is, high-speed data communications mediums, powerful processors, and speed optimized audio signal processing functions all work to decrease the latency period. An alternative approach to the latency problem is to mask the latency, for example, through time-scale modification of the audio signals. Both linear and non-uniform time-scale modification techniques are available. For more background on these different compression techniques, please see Covell et al.&#39;s article entitled “MACH1: NONUNIFORM TIME-SCALE MODIFICATION OF SPEECH” published in the  Proceedings of the IEEE International Conference on Acoustics, Speech and Signal Processing , May 12-15, 1998, Seattle Wash., which is incorporated herein by reference. 
     In most situations, the primary purpose of the shared audio space is to share speech and speech-like signals. However, non-speech signals may at times overpower the desired speech signals. A variety of pre-existing techniques for distinguishing speech signals from non-speech signals are available in the field. For example, see Scheirer and Slaney&#39;s article entitled “CONSTRUCTION AND EVALUATION OF A ROBUST MULTIFEATURE SPEECH/MUSIC DISCRIMINATOR” published in  Proc. ICASSP -97, April 21-24, Munich, Germany. See, also, Ngo and Bhadkamkar&#39;s article entitled “ADAPTIVE BLIND SEPARATION OF AUDIO SOURCES BY A PHYSICALLY COMPACT DEVICE USING SECOND ORDER STATISTICS.” Once a technique for distinguishing speech signals has been selected, the distinguished speech signals may be emphasized to create the desired shared audio space. 
     Along these lines, FIG. 9 illustrates a flow chart of a calibration method  600  in accordance with one embodiment of the present invention. In properly configuring the above auralization properties an initial calibration process can be very helpful. The method  600  provides one possible calibration method for setting up the auralization properties for the electronic audio connection systems of the present invention. 
     In a step  602 , the calibration method  600  begins. The method  600  may be initiated each time the electronic audio connection system is powered-up, or may occur when initiated by a user or during a first use of the system. In any event, in a step  604  the method  600  aurally transmits a known (“test”) audio pattern through the speakers. Because the test audio pattern is known, the method in a step  606  can analyze the received results, checking for room aural properties such as echo and reverberation, and confirming that the received pattern matches the expected received pattern. Then in a step  608 , the method  600  calibrates and sets the auralization properties as desired. This may involve adjusting parameters used in the different audio signal processing functions, but may also include adjusting the positions of the speakers and microphones with the separate physical spaces as required. 
     While this invention has been described in terms of several preferred embodiments, there are alterations, permutations, and equivalents that fall within the scope of this invention. It should also be noted that there are many alternative ways of implementing both the process and apparatus of the present invention. 
     The examples presented in the above-description focused on personal room-like physical spaces. However, the present invention contemplates the sharing of an audio space across all kinds of physical spaces. For example, a telecommuter may couple the hallway outside of his or her home office to the hallway outside his or her office at work, creating the impression on both ends of his or her physical presence at the work office. As another example, an outdoor space could be coupled with other indoor spaces. 
     The above-described embodiments are particularly well-suited for implementation using wireless communications technology. This includes wireless speaker and microphone device technology. However, the speaker and microphone devices may be hard-wired, or may a combination of hard-wire and wireless technology. 
     As will be appreciated, in communicating the quantity of data quantities contemplated herein it is likely that data compression will be involved in many embodiments. Standard digital audio data compression techniques are well familiar to those skilled in the art and well suited for the present invention. Likewise, standard auto gain control (AGC) or volume control techniques are helpful in creating a useful shared audio space. Signal processing mechanisms may also be used to localize the user as he or she moves about the physical space. This localization information is useful in further signal processing for both the input and output devices (i.e., microphones and speakers). 
     The present invention also provides a mechanism for accomplishing “one-touch” conferencing between multiple parties. The stereo, immersive nature of the present invention allows such multi-party conferencing to feel as if the parties were positioned around a table, instead of having all the voices in a teleconference come at the listener from a single telephone speaker sitting on a table. 
     It is therefore intended that the scope of the invention be interpreted as including all such alterations, permutations, and equivalents.