Patent Application
20160302009
Given the differing interests of various users (e.g., ordinary people such as pedestrians, shoppers, etc.) in public spaces such as malls, gyms, museums and airport lounges, the possibility of personalizing a desired one of various available audio streams to listen to, is appealing. For example, in an airport lounge or a gym where many screens broadcast different channels, different patrons may wish to listen to different audio streams associated with different channels. One patron may wish to listen to an audio stream associated with a screen broadcasting the latest news while another patron may wish to listen to another audio stream associated with a screen broadcasting the latest sporting event. In other words, different patrons may wish to have different personalized audio streams.
The current solution for providing personalized audio stream involves the use of headphones which need to be plugged into a source with appropriate input signal or a channel broadcasting the relevant sound. The current solutions require physical devices, capable of receiving audio streams, to be attached to the head or ears of a user. Utilizing the current solutions in large public spaces is not desirable as physical (e.g. hardwire) connection between headphones of different users and the sources of different audios is often inconvenient to the end user and to implement. The example embodiments of the present application, as will be described below, provide an all-acoustic and more practical alternative to the current state of the art.
Some example embodiments relate to methods and/or systems for localizing audible audio streams so that different users in a common public space can listen to any one the audio streams without using headphones and without hearing other audio streams.
One example embodiment is a system. The system comprises a processing unit configured to compute transmit signals and an array of speakers. The array of speakers can be in wired or wireless communication with the processing unit, each of the speakers of the array installed at different locations in a common setting. Each of the speakers of the array, upon receiving the transmit signals, may simultaneously transmit both a first audio stream and a different second audio stream into the setting from the speakers. The first audio stream transmitted from the speakers aggregate in the vicinity of a first location in the setting to form an aggregated first audio stream that is audible to human hearing, and, the second audio stream transmitted from the speakers do not aggregate at the first location. The second audio stream transmitted from the speakers aggregate in the vicinity of a different second location in the setting to form an aggregated second audio stream that is audible to human hearing, and, the first audio stream transmitted from the speakers do not aggregate at the second location.
In any embodiments, each of the speakers can further include a receiver to receive pilot audio signals transmitted from the first location and the second location. In any such embodiments the processing unit may compute the transmit signals upon receiving an audio stream request from the first location or the second location. In some embodiments the audio stream request is a wireless signal from the first location or the second location while in some embodiments the audio stream request is an optical signal from the first location or the second location.
In any embodiments, the first location and the second location can each include separate electronic devices, the electronic devices each having a receiver to receive a training interval instruction from the processor, and, a transmitter to transmit a pilot audio signal upon receipt of the training interval instruction. In some such embodiments, the training interval instruction causes the transmitter of each of the electronic devices to simultaneously transmit the pilot audio signals. In some such embodiments, the simultaneously transmitted pilot audio signals are acoustic training signals that are mutually orthogonal over intervals of frequency such that acoustic channel frequency responses from the electronic devices are approximately constant. In some such embodiments, the electronic devices are mobile electronic devices and the first and second locations are non-fixed locations, while in other such embodiments, the electronic devices are fixedly positioned and the first and second locations are fixed locations.
In any embodiments, the common setting is a shopping mall and the first and second locations correspond to different item-for-sale displays in the shopping mall. In any such embodiments, the common setting includes a first video screen presenting a first video broadcast associated with the first audio stream and second video screen presenting a second different video broadcast associated with the second audio stream.
In any embodiments, computation of the transmit signals can include computing, in the processing unit, audio channel state information based upon pilot audio signals transmitted from the first and second locations, received by each of the speakers and transmitted to the processing unit. Computation of the transmit signals can also include computing in the processing unit, a pre-code matrix based on the audio channel state information. Computation of the transmit signals can also include multiplying in the processing unit, an available first audio stream by the pre-code matrix to generate the first audio stream. Computation of the transmit signals can also include multiplying in the processing unit, an available second audio stream by the pre-code matrix to generate the second audio stream. In some such embodiments, computing the audio channel state information can include computing an acoustic channel impulse response matrix between each of the speakers and at least one of the first location or the second location. In some such embodiments, the pre-code matrix is of either a conjugate beamforming type or a zero-forcing beamforming type.
In any embodiments, each one of the speakers can include separate ones of the processing units, each of the separate processing units configured to compute the transmit signals and then communicate the transmit signals to the respective speaker of the audio unit.
Another embodiment is a method comprising forming a plurality of localized audible audio streams. Transmit signals are computing in a processing unit. The transmit signals are communicated from the processing unit to an array of speakers that can be wired or wireless communication with the processing unit. Each of the speakers of the array are installed at different locations in a common setting. Each of the speakers of the array, upon receiving the transmit signals, simultaneously transmit both a first audio stream and a different second audio stream into the setting from the speakers. The first audio stream transmitted from the speakers aggregate in the vicinity of a first location in the setting to form an aggregated first audio stream that is audible to human hearing, and, the second audio stream transmitted from the speakers do not aggregate at the first location. The second audio stream transmitted from the speakers aggregate in the vicinity of a different second location in the setting to form an aggregated second audio stream that is audible to human hearing, and, the first audio stream transmitted from the speakers do not aggregate at the second location.
In any embodiments of the method, computation of the transmit signals can include computing, in the processing unit, audio channel state information based upon pilot audio signals transmitted from the first and second locations, received by each of the speakers and transmitted to the processing unit. Computation of the transmit signals can also include computing in the processing unit, a pre-code matrix based on the audio channel state information. Computation of the transmit signals can also include multiplying in the processing unit, an available first audio stream by the pre-code matrix to generate the first audio stream. Computation of the transmit signals can also include multiplying in the processing unit, an available second audio stream by the pre-code matrix to generate the second audio stream.
In any embodiments, computing the audio channel state information can include computing an acoustic channel impulse response matrix between each of the speakers and at least one of the first location or the second location. In some such embodiments, the pre-code matrix can be either a conjugate beamforming type or a zero-forcing beamforming type.
In one example embodiment, a system for localizing an audio stream includes a processor. The processor is configured to determine channel state information of an acoustic channel between a plurality of speakers and at least one device of a plurality of devices, the at least one device requesting the audio stream from among available audio streams. The processor is further configured to determine transmit signals for transmitting audio signals representing the available audio streams to the plurality of devices, the determined transmit signals being based on at least the determined channel state information such that the requested audio stream is more audible to a user associated with the at least one device compared to other users associated with other ones of the plurality of devices.
In yet another example embodiment, the processor is configured to send the determined transmit signals to the plurality of speakers for transmission to the plurality of devices.
In yet another example embodiment, each of the plurality of speakers transmits the audio signals corresponding to the available audio streams.
In yet another example embodiment, the processor is configured to determine the transmit signals by determining pre-codes based on the determined channel state information and applying the determined pre-codes and transmission power coefficients to the audio signal to determine the transmit signals.
In yet another example embodiment, the processor is configured to determine the pre-codes based on one of conjugate beamforming or zero-forcing beamforming.
In yet another example embodiment, the processor is configured to determine the channel state information by measuring a channel impulse response between each of the plurality of speakers and the at least one device.
In yet another example embodiment, the processor is configured to measure the channel impulse response by receiving from each of the plurality of speakers, an acoustic training signal transmitted by the at least one device and received at each of the plurality of speakers.
In yet another example embodiment, the acoustic training signal transmitted by the at least one device and other acoustic training signals transmitted by other ones of the plurality of devices are mutually orthogonal.
In yet another example embodiment, the processor is further configured to detect a presence of the at least one device in a setting in which the plurality of speakers are installed.
In yet another example embodiment, the processor is configured to detect the presence of the at least one device by receiving a request for the audio stream from the at least one device.
In one example embodiment, a method for localizing an audio stream includes determining channel state information of an acoustic channel between a plurality of speakers and at least one device of a plurality of devices, the at least one device requesting the audio stream from among available audio streams. The method further includes determining transmit signals for transmitting audio signals representing the available audio streams to the plurality of devices, the determined transmit signals being based on at least the determined channel state information such that the requested audio stream is more audible to a user associated with the at least one device compared to other users associated with other ones of the plurality of devices.
In yet another example embodiment, the method further includes sending the determined transmit signals to the plurality of speakers for transmission to the plurality of devices.
In yet another example embodiment, each of the plurality of speakers transmits the audio signals corresponding to the available audio streams.
In yet another example embodiment, the determining the transmit signals determines the transmit signals by determining pre-codes based on the determined channel state information and applying the determined pre-codes and transmission power coefficients to the audio signal to determine the transmit signals.
In yet another example embodiment, the determining the pre-codes determines the pre-codes based on one of conjugate beamforming or zero-forcing beamforming.
In yet another example embodiment, the determining the channel state information determines the channel state information by measuring a channel impulse response between each of the plurality of speakers and the at least one device.
In yet another example embodiment, the measuring measures the channel impulse response by receiving from each of the plurality of speakers, an acoustic training signal transmitted by the at least one device and received at each of the plurality of speakers.
In yet another example embodiment, the acoustic training signal transmitted by the at least one device and other acoustic training signals transmitted by other ones of the plurality of devices are mutually orthogonal.
In yet another example embodiment, the method further includes detecting a presence of the at least one device in a setting in which the plurality of speakers are installed.
In yet another example embodiment, the detecting detects the presence of the at least one device by receiving a request for the audio stream from the at least one device.
Example embodiments will become more fully understood from the detailed description given herein below and the accompanying drawings, wherein like elements are represented by like reference numerals, which are given by way of illustration only and thus are not limiting of the present disclosure, and wherein:
Various embodiments will now be described more fully with reference to the accompanying drawings. Like elements on the drawings are labeled by like reference numerals.
Accordingly, while example embodiments are capable of various modifications and alternative forms, the embodiments are shown by way of example in the drawings and will be described herein in detail. It should be understood, however, that there is no intent to limit example embodiments to the particular forms disclosed. On the contrary, example embodiments are to cover all modifications, equivalents, and alternatives falling within the scope of this disclosure.
Although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of this disclosure. As used herein, the term “and/or,” includes any and all combinations of one or more of the associated listed items.
When an element is referred to as being “connected,” or “coupled,” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. By contrast, when an element is referred to as being “directly connected,” or “directly coupled,” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between,” versus “directly between,” “adjacent,” versus “directly adjacent,” etc.).
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an”, and the are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising,”, “includes” and/or “including”, when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may in fact be executed substantially concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
Specific details are provided in the following description to provide a thorough understanding of example embodiments. However, it will be understood by one of ordinary skill in the art that example embodiments may be practiced without these specific details. For example, systems may be shown in block diagrams so as not to obscure the example embodiments in unnecessary detail. In other instances, well-known processes, structures and techniques may be shown without unnecessary detail in order to avoid obscuring example embodiments.
In the following description, illustrative embodiments will be described with reference to acts and symbolic representations of operations (e.g., in the form of flow charts, flow diagrams, data flow diagrams, structure diagrams, block diagrams, etc.) that may be implemented as program modules or functional processes include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types and may be implemented using existing hardware at existing network elements. Such existing hardware may include one or more Central Processing Units (CPUs), digital signal processors (DSPs), application-specific-integrated-circuits, field programmable gate arrays (FPGAs), computers or the like.
Although a flow chart may describe the operations as a sequential process, many of the operations may be performed in parallel, concurrently or simultaneously. In addition, the order of the operations may be re-arranged, and certain operations may be omitted or added to the process. A process may be terminated when its operations are completed, but may also have additional steps not included in the figure. A process may correspond to a method, function, procedure, subroutine, subprogram, etc. When a process corresponds to a function, its termination may correspond to a return of the function to the calling function or the main function.
As disclosed herein, the term “storage medium” or “computer readable storage medium” may represent one or more devices for storing data, including read only memory (ROM), random access memory (RAM), magnetic RAM, core memory, magnetic disk storage mediums, optical storage mediums, flash memory devices and/or other tangible machine readable mediums for storing information. The term “computer-readable medium” may include, but is not limited to, portable or fixed storage devices, optical storage devices, and various other mediums capable of storing, containing or carrying instruction(s) and/or data.
Furthermore, example embodiments may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware, or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine or computer readable medium such as a computer readable storage medium. When implemented in software, a processor or processors will perform the necessary tasks.
A code segment may represent a procedure, function, subprogram, program, routine, subroutine, module, software package, class, or any combination of instructions, data structures or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and/or receiving information, data, arguments, parameters or memory content. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc.
As will be described below, the example embodiments of the present application enable different users in a given public space to listen to (e.g., personalize) one of a plurality of different available audio streams without using headphones. The example embodiments enable localization and personalization of acoustic signals in an immediate vicinity of one or more individual users (e.g., listeners) among a large number of individuals present in a given public space.
This localization and personalization of acoustic signals is enabled by creating sufficient coherent sound energy in the immediate vicinity of a user by aggregating a number of low energy audio signals transmitted from a large speaker array in the immediate vicinity of the user. In other words, while all audio signals associated with different audio streams are transmitted to all users in a given public space, depending on a desired/requested audio stream by any of the users in the public space, the low energy audio signals corresponding to the desired/requested audio stream are selectively aggregated in the vicinity of a requesting user while the other low energy audio signals of non-desired/non-requested audio streams are not aggregated and thus may at most appear as background noise to the requesting user.
The system 100 may further include a number of speakers 104-1 to 104-3. The speakers 104-1 to 104-3 may be referred to as speaker array 104. The number of speakers in the speaker array 104 is not limited to that shown in
The speakers of the speaker array 104 may each include electrical components such as a transducer, a digital-to-analog converter and an analog-to-digital converter for communication with users present in the setting and/or a central processor, both of which will be described below. The speakers of the speaker array 104 may further include a microphone for receiving signals (e.g., acoustic signals) from users.
The speakers of the speaker array 104 may be positioned near one another or may alternatively be positioned up to a few hundred feet apart. Each of the speakers of the speaker array 104 may broadcast the audio signals associated with the screens 102-1 and 102-2. The connection between the speakers of the speaker array 104 and the corresponding screen of the screens 102-1 and 102-2 may be a wired connection or a wireless connection.
Furthermore, there may be several users 106 and 108 present in the system 100. The number of users is not limited to that shown in
As shown in
As will be described below, the users 106 and 108 may each have an associated portable device (e.g., a mobile device such as a cellular phone, a tablet, a portable computer, a pager or any other electronic device capable of communicating with the speakers of speaker array 104), with which the speaker array 104 communicates to receive acoustic channel state information (CSI) between each of the users 106 and 108 and each of the speakers of the speaker array 104. The received CSI(s) will then be transmitted to a processor 114, which will be described below. The processor 114 determines an appropriate pre-codes/gain matrix using the received CSI, with which the audio signals of the available audio streams may be multiplied and then transmitted by each speaker of the speaker array 104 to the users 106 and 108.
The portable devices associated with the users 106 and 108 may include at least a processor, a speaker, a microphone, a transducer, an analog-to-digital converter and a digital-to-analog converter for communication with the speakers of the speaker array 104. Hereinafter and throughout the specification, the terms user device, portable device and user may be used interchangeably.
The users 106 and 108 may enter or leave the setting 101 at any time and/or may move around within the setting 101. As will be described below, depending on the amount of movement within the setting 101, a particular user's CSI may change and may thus need to be measured again/updated.
As shown in
In one example embodiment and by implementing the method of
In one example embodiment, the speakers of the speaker array 104 may individually be configured to cooperatively carry out the process described below with respect to
In one example embodiment, the setting, as mentioned above, may be a museum or a window display of a clothing store in a shopping mall. Accordingly, the screens 102-1 and 102-2 may not necessarily broadcast videos but may rather correspond to different sculptures, paintings, items displayed for sale, etc., each of which may have an audio stream associated therewith. The associated audio stream may describe the story behind a given sculpture or painting or describe the characteristics of the items displayed for sale. As patrons walk around the museum or the store, they may wish to listen to a particular audio stream associated with a particular item on display without using headsets or hearing other available audio streams. The example embodiments and the methods described below enable a patron to do so.
The system 200 may include a number of speakers 204-1 to 204-8. The speakers 204-1 to 204-8 may be referred to as speaker array 204. The speaker array 204 may function in the same manner as the speaker array 104. The number of speakers in the speaker array 204 is not limited to that shown in
In one example embodiment, the speaker array 204 may be placed around or within the setting 201 of a shopping mall, a particular store in a shopping mall, an entrance of a gym, an entrance to a museum, etc. The speaker array 204 may broadcast a particular audio (e.g., a song, an advertisement, a welcoming message, etc.), that may only be audible as an individual 202 (e.g., a patron, a customer, etc.) passes through such entrance 201 but may not be audible a few feet from the entrance.
While in
As shown in
In one example embodiment, the speakers of the speaker array 204 may individually be configured to carry out the process described below with respect to
In the example embodiments described with respect to
As shown by the broken lines in
Hereinafter, a method for localizing/personalizing audio, to be implemented by the processors and/or individual speakers described above with reference to
At S300, the processor 114 receives a request for an audio stream from a user (e.g., user 106 and/or 108) via the speaker array 104 in for example, the setting shown in
In one example embodiment and within the setting shown in
The user may have a mobile device (e.g., the portable device described above) associated therewith. The mobile device may have an application running thereon, which detects a presence of available audio streams within the setting shown in
For example, in the setting shown in
At S310, the processor 114 may determine channel state information (CSI) of an acoustic channel between the user's mobile device and the speakers of the speaker array 114 that broadcasts the chosen audio stream. The process of determining the CSI will now be described with reference to
At S400, the processor 114 may direct/inform the mobile device associated with the user to send a pilot signal (which may also be referred to as an acoustic and/or audio training signal) to the speakers of the speaker array 104. In one example embodiment, the processor 114 may direct/inform the user's mobile device to transmit the pilot signal via a conventional wireless link or a free-space optical link.
Upon receiving an indication, the mobile device of the user may transmit the pilot signal to each of the speakers of the speaker array 104. At S410, the processor 114 may receive the pilot signal from the mobile device of the user via each speaker of the speaker array 104.
At S420, the processor 114 determines the CSI as an estimate of the impulse response of each of the acoustic channels between the mobile device of the user and each of the speakers of the speaker array 114, over which the mobile device of the user transmitted the pilot signal to each speaker of the speaker array 104. In one example embodiment, the channel impulse response may be denoted as gmk(t), where m denotes the mth speaker of the speaker array 104 and k denotes the kth user.
For purposes of discussion, we assume in general that there are M speakers in a speaker array and K users present in a setting. Therefore, in the example embodiment of
The processor 114 may determine each of the acoustic channel impulse responses using any known channel impulse response estimation methods.
The process of
Significant correlation among pilot signals transmitted by different users may result in what is known as pilot contamination. For example, when two users transmit the same pilot signals, the processor 114 may process the received pilot signal by obtaining a linear combination of the two acoustic channels of the two users. Accordingly, when the processor 114 uses linear pre-coding to transmit an audio signal to a first one of the two users, it may inadvertently direct the speakers of the speaker array 104 to transmit the same audio signal to the second user, and vice-versa. Thus pilot contamination results in coherent directed interference that may only worsen as the number of the speakers of the speaker array 104 increases.
Accordingly and in one example embodiment, such pilot contamination may be utilized for multicasting, in which the same audio signal is to be transmitted to a multiplicity of users (e.g., when more than one user in the setting requests the same audio signal. For example, users 106 and 108 in
Furthermore and in one example embodiment, the training interval is performed every time a new user enters the setting 100. In yet another example embodiment, whenever the user moves significantly (e.g., more than ¼ of a wavelength), the training interval for such user is renewed. In yet another example embodiment, when the acoustic conditions in the setting changes (e.g., due to the movement of people, vehicles, etc.), the training interval for such user and/or setting is renewed.
At S430, the processor may revert back to S310 of
Referring back to
At S320, the processor 114 determines pre-codes for pre-coding audio signals of the audio stream. In one example embodiment, the processor 114 determines pre-codes for pre-coding audio signals of all the available audio streams that are transmitted by all of the speakers of the speaker array 104. In one example embodiment, the processor 114 may determine the pre-codes as follows.
There may be two different forms of pre-coding referred to as conjugate beam-forming and zero-forcing. The conjugate beam-forming and the zero-forcing pre-coding are respectively shown by the following:
A(f)={circumflex over (G)}*(f), (1)
A(f)={circumflex over (G)}*(f)(ĜT(f){circumflex over (G)}*(f))−1 (2)
Given the channel impulse response estimate matrix G, as determined at S420, in one example embodiment, the processor 114 determines the pre-code matrix A, per Eq. (1) or (2) above.
Once the processor 114 determines the pre-codes, at S330, the processor 114 pre-codes the audio signals of the available audio stream(s) and determines the transmit signals (which may refer to audio signals determined for transmission) to be communicated to the speakers of the speaker array 104 for transmission to the users 106 and 108. In one example embodiment, the processor 114 determines the transmit signals with the following assumptions taken into consideration.
As described above, there are K users and M speakers and the audio signal associated with the audio stream requested by the k-th user, is denoted as qk(f) in frequency domain. Then, the K intended audio signals are mapped into the M signals transmitted by the speaker array 104 via, for example, a linear pre-coding operation.
The transmit signals may be designated as xk(f) in frequency domain, which may in turn be sent to the speakers of the speaker array 104, for subsequent transmission to the users 106 and 108. The signal x(f), in matrix form and in frequency-domain representation, may be determined as follows:
x(f)=A(f)Dηq(f), (3)
where Dη is a K×K diagonal matrix of power-control coefficients which denotes the power with which each speaker of the speaker array 104 transmits an acoustic signal. Dη is not frequency dependent. A(f) is a M×K pre-coding matrix determined at S320 and q(f) is a vector of audio signals of all the available audio streams (e.g., the audio signals of all the available audio streams for screens 102-1 and 102-2.
Knowing A(f), Dη and q(f), at S330, the processor 114 determines the transmit signals x(f), per Eq. 3.
The performance of linear pre-coding improves monotonically with the number of speakers in the speaker array 104. The ability to transmit audio selectively to the multiplicity of users improves, and the total radiated power required for the multiplexing is inversely proportional to the number of speakers in the speaker array 104.
In some example embodiments, pre-coding based on zero-forcing tends to be superior to pre-coding based on conjugate beamforming when performance is noise limited (rather than interference limited) and the users enjoy high Signal to Interference and Noise Ratios (SINRs). While zero-forcing may require a higher computational burden than conjugate beamforming, the implementation of linear pre-coding of Eq. 3 based on conjugate beam-forming may require more total effort than the computation of the linear pre-coding of Eq. 3 based on zero-forcing. An example advantage of conjugate beamforming over zero-forcing in that conjugate beamforming permits decentralized array architecture such that every speaker performs its own linear pre-coding independent of the other transducers. In other words, instead of utilizing a centralized processor 114, as shown in
At S340, the processor 114 may send the transmit signal x determined according to Eq. 3 above, to the speakers of the speaker array 104 for transmission to the users 106 and 108. The transmit signal x may be received at the users 106 and 108 as y, which may be represented in the frequency domain as:
y(f)=GT(f)x(f). (4)
where “T” denotes a transpose of the channel impulse response matrix G, as estimated and described above. Eq. (4) may be converted to time-domain, in which case y may be a convolution of GT(t) and x(t).
In one example embodiment and as described above, the pre-coded audio signals (e.g., the entries of the transmit signal matrix x) are low-energy acoustic signals that are transmitted over the air such that the low energy audio signals corresponding to the screen 102-1 aggregate in a vicinity of the user 106. Accordingly, the audio stream associated with the screen 102-1 will have an energy level above a threshold and is audible to the user 106 while the audio stream associated with the screens 101-2 is inaudible or are less audible to the user 106 (e.g. appear as background noise).
Similarly, the low energy audio signals corresponding to the audio stream associated with the screen 102-2 aggregate in a vicinity of the user 108. Accordingly, the audio stream associated with the screen 102-2 will have an energy level above a threshold and is audible to the user 108 while the audio stream associated with the screens 102-1 is inaudible or are less audible to the user 106 (e.g. appear as background noise).
In one example embodiment, the threshold described above is a configurable parameter and may correspond to a threshold above which sound is audible to a human ear.
In one example embodiment, the processor 114 may determine the pre-codes but the process of pre-coding the audio signals may be performed by processors associated with the speakers of the speaker array 104. This example embodiment will be described with reference to
At S530, the processor 114 may send the pre-codes determined at S520 to the speakers of the speaker array 104.
Thereafter, the speakers, via their associated processors, perform the pre-coding in the same manner as that done at S330 as described above with reference to
In one example embodiment and as described above, each speaker of the speaker array 104 transmits a low-energy signal of the audio stream to the users 106 and 108. The low-energy signals, of an audio stream requested by one of the users 106 and 108, from each speaker of the speaker array 104 aggregate in the vicinity of the one of the users 106 and 108 who requested the audio stream such that the energy of the aggregated audio signals of the requested audio stream is above a threshold, and the audio stream becomes more audible to the requesting one of the users 106 and.
In one example embodiment, the threshold described above is a configurable parameter and may correspond to a threshold above which sound is audible to a human ear.
Variations of the example embodiments are not to be regarded as a departure from the spirit and scope of the example embodiments, and all such variations as would be apparent to one skilled in the art are intended to be included within the scope of this disclosure.
This is a continuation application of U.S. patent application Ser. No. 14/502,058 of the same title, filed on Sep. 30, 2014, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14502058 | Sep 2014 | US |
| Child | 15188046 | US |
