Patent Description:
This application generally relates to an array microphone module and systems therefore. In particular, this application relates to an array microphone module that is capable of being connected with other like array microphone modules to create a configurable system of modular array microphone modules.

Conferencing environments, such as conference rooms, boardrooms, video conferencing applications, and the like, can involve the use of microphones for capturing sound from various audio sources active in such environments. Such audio sources may include humans speaking, for example. The captured sound may be disseminated to a local audience in the environment through amplified speakers (for sound reinforcement), or to others remote from the environment (such as via a telecast and/or a webcast).

Traditional microphones typically have fixed polar patterns and few manually selectable settings. To capture sound in a conferencing environment, many traditional microphones are often used at once to capture the audio sources within the environment. However, traditional microphones tend to capture unwanted audio as well, such as room noise, echoes, and other undesirable audio elements. The capturing of these unwanted noises is exacerbated by the use of many microphones.

Array microphones provide benefits in that they have steerable coverage or pick up patterns, which allow the microphones to focus on the desired audio sources and reject unwanted sounds such as room noise. The ability to steer audio pick up patterns provides the benefit of being able to be less precise in microphone placement, and in this way, array microphones are more forgiving. Moreover, array microphones provide the ability to pick up multiple audio sources with one array microphone or unit, again due to the ability to steer the pickup patterns.

However, array microphones have certain shortcomings, including the fact that they are typically relatively larger than traditional microphones, and their fixed size often limits where they can be placed in an environment. Moreover, when larger numbers of array microphones are used, the microphone elements of one array microphone do not work in conjunction with the microphone elements of another array microphone. Systems of array microphones can often be difficult to configure properly. Also, array microphones are usually significantly more costly than traditional microphones. Given these shortcomings, array microphones are usually custom fit to their application, causing them to be primarily used in large scale, highly customized, and costly installations.

Accordingly, there is an opportunity for systems that address these concerns. More particularly, there is an opportunity for modular systems including an array microphone module that is easily scalable, flexible in mounting position, and self configuring to allow the system to optimally detect sounds from an audio source, e.g., a human speaker, and reject unwanted noise and reflections. <CIT>, for example, discloses systems and methods for digitally linking multiple microphones and managing microphones signals.

The invention is intended to solve the above-noted problems by providing systems and methods that are designed to, among other things: (<NUM>) provide an array microphone module that is modular and scalable, and can be connected to other such modules to create array microphone systems of easily customized shapes and sizes; and (<NUM>) provide an array microphone system comprising an array processor connected to a plurality of such array microphone modules to achieve a self-configuring array microphone system with improved directional sensitivity.

The independent claim relates to an embodiment of the invention.

In an embodiment useful for understanding the invention, a microphone module comprises a housing, an audio bus, and a first plurality of microphones supported by the housing. Each of the first plurality of microphones is in communication with the audio bus. The microphone module further comprises a module processor in communication with the first plurality of microphones and the audio bus. The module processor is configured to detect the presence of an array processor in communication with the audio bus, detect the presence of a second microphone module in communication with the audio bus, and configure the audio bus to pass audio signals from both the first plurality of microphones and the second microphone module to the array processor.

In another embodiment useful for understanding the invention, a modular array microphone system comprises an array processor and a microphone module. The microphone module comprises a housing, an audio bus in communication with the array processor, and a plurality of microphones supported by the housing, each of the plurality of microphones in communication with the audio bus. The microphone module further comprises a module processor in communication with the plurality of microphones and the audio bus, the module processor configured to detect the presence of the array processor connected to the audio bus, detect the presence of a second microphone module in communication with the audio bus, and configure the audio bus to pass audio from both the plurality of microphones and the second microphone module to the array processor.

In yet another embodiment useful for understanding the invention, a microphone module comprises a housing, having a length, a first end and a second end, an audio bus, and a plurality of microphones arranged along the length of the housing, each of the plurality of microphones positioned generally in a direction transverse to the length, each of the plurality of microphones in communication with the audio bus. The microphone module further comprises a module processor in communication with the plurality of microphones and the audio bus, the module processor configured to detect the presence of an array processor in communication with the audio bus, detect the presence of a second microphone module in communication with the audio bus, and configure the audio bus to pass audio from both the plurality of microphones and the second microphone module to the array processor.

In yet another embodiment useful for understanding the invention, a microphone module comprises a housing, an audio bus, and a plurality of microphones supported by the housing, each of the plurality of microphones in communication with the audio bus. The microphone module further comprises a module processor in communication with the plurality of microphones and the audio bus, the module processor configured to detect the presence of an array processor in communication with the audio bus and configure the audio bus to pass audio signals from the plurality of microphones to the array processor, wherein the array processor creates at least one output audio stream formed from a subset of audio signals detected by the plurality of microphones, the subset based upon a position of the module in a chain of modules.

In yet another embodiment useful for understanding the invention, a modular array microphone system comprises a first microphone module and a second microphone module. Each of the first and second microphone modules comprises a housing, having a first end, a middle portion, a second end, and a length extending from the first end to the second end, an audio bus, and a plurality of microphones supported by the housing and generally dispersed across the length of the housing, each of the plurality of microphones in communication with the audio bus, wherein the plurality of microphones includes a first cluster of microphones proximate the first end, a second cluster of microphones proximate the second end and a third cluster of microphone proximate the middle portion.

In yet another embodiment useful for understanding the invention, a modular array microphone system comprises a first microphone module connected to a second microphone module. Each of the first and second modules comprises a housing, having a first end, a middle portion, a second end, and a length extending from the first end to the second end, an audio bus, and a plurality of microphones supported by the housing and generally dispersed across the length of the housing, each of the plurality of microphones in communication with the audio bus. The plurality of microphones includes a first cluster of microphones proximate the first end, a second cluster of microphones proximate the second end and a third cluster of microphone proximate the middle portion. The second end of the first microphone module is connected to the first end of the second microphone module at a connection point to form a composite array microphone, the composite array microphone comprising a first composite cluster, a second composite cluster and a third composite cluster.

These and other embodiments, and various permutations and aspects, will become apparent and be more fully understood from the following detailed description and accompanying drawings.

The description that follows describes, illustrates and exemplifies one or more particular embodiments.

The scope of the invention is intended to cover all such embodiments that fall within the scope of the appended claims.

It should be noted that in the description and drawings, like or substantially similar elements may be labeled with the same reference numerals. However, sometimes these elements may be labeled with differing numbers, such as, for example, in cases where such labeling facilitates a more clear description. Additionally, the drawings set forth herein are not necessarily drawn to scale, and in some instances proportions may have been exaggerated to more clearly depict certain features. Such labeling and drawing practices do not necessarily implicate an underlying substantive purpose.

With respect to the exemplary systems, components and architecture described and illustrated herein, it should also be understood that the embodiments may be embodied by, or employed in, numerous configurations and components, including one or more systems, hardware, software, or firmware configurations or components, or any combination thereof, as understood by one of ordinary skill in the art. Accordingly, while the drawings illustrate exemplary systems including components for one or more of the embodiments contemplated herein, it should be understood that with respect to each embodiment, one or more components may not be present or necessary in the system.

Turning to <FIG>, an exemplary embodiment of a microphone module <NUM> for detecting sound from an external acoustic source according to the present invention is depicted, which may be any frequency of sound pressure, including, for example, an audio source. The microphone module <NUM> generally comprises an elongated housing <NUM> having a first end <NUM> and a second end <NUM>. The microphone module <NUM> generally has a length (L) extending from the first end <NUM> to the second end <NUM>. A plurality of microphones <NUM> arranged in an array <NUM> are supported by the housing <NUM> of the module <NUM>. In an embodiment, the microphones <NUM> are mounted inside of and supported by the housing <NUM>, but in alternative embodiments, the microphones <NUM> may be mounted on the exterior of the housing <NUM>, partially within and partially outside of the housing <NUM>, or in other manners such that the microphones <NUM> are structurally supported by the housing <NUM>.

In the embodiment shown in <FIG>, a quantity of twenty-five (<NUM>) microphones <NUM> are arranged in an array <NUM> and mounted within the housing <NUM>. To permit the microphones <NUM> of the module <NUM> to receive sound, one or more apertures <NUM> are formed into the housing <NUM> to allow sound to pass through the housing <NUM>. In the embodiment depicted in <FIG>, a single slot-shaped aperture <NUM> is formed into the housing <NUM> of the module <NUM>, and is optionally covered in a porous screen, as shown, to protect the microphones <NUM> and other internal components of the module <NUM>. In other embodiments, greater numbers of apertures <NUM> may be formed in the housing <NUM> to permit sound from external sound sources to reach the microphones <NUM> supported by the housing <NUM> of the module <NUM>. The apertures <NUM> may take on various forms, including slots, slits, perforations, holes, and other arrangements of openings in the housing <NUM>.

In the embodiment of <FIG>, the microphones <NUM> are generally arranged in a linear fashion, forming a linear array <NUM> positioned along the length (L) of the microphone module <NUM>. While the microphones <NUM> are generally positioned along the length (L) of the module <NUM>, they need not be positioned along a straight line, and can be positioned in various configurations throughout the housing <NUM> of the module <NUM>. In an embodiment, the microphones <NUM> are generally positioned transverse to the length (L), and may be positioned proximate the aperture <NUM> in the housing <NUM> to detect sounds from external sources outside of the module <NUM>. The microphones <NUM> need not be parallel to one another, but in an embodiment, are preferably positioned transverse to the length (L) of the housing <NUM>.

The microphones <NUM> may be directional microphones, which are positioned in a certain orientation with respect to the aperture <NUM> to detect an audio source outside of the housing <NUM>. Alternatively, the microphones <NUM> may be non-directional, or omni-directional microphones, which need not be positioned in a particular manner relative to the aperture <NUM> or housing <NUM>, so long as acoustic waves can penetrate the housing <NUM> via the aperture <NUM> and reach the microphones <NUM>. In other embodiments, other arrays <NUM> comprising alternative geometric arrangements of microphones <NUM> may be utilized. For example, the array <NUM> may comprise microphones <NUM> arranged in circular or rectangular configurations, or having nested concentric rings of microphones <NUM> across a plane. The length of the housing <NUM> need not be the largest dimension of the module <NUM>, but rather can be any dimension of the module <NUM> along which the microphones <NUM> are positioned. Thus, in alternative embodiments, the layout and arrangement of the microphones <NUM> may be any variety of patterns, including two-dimensional and three-dimensional arrangements of microphones <NUM> within the housing <NUM>. These arrangements can include arced, circular, square, rectangular, cross-shaped, intersecting, parallel or other shaped arrangements of microphones <NUM>.

The microphone module <NUM> includes a module processor <NUM> and an audio bus <NUM>, both of which are positioned within the housing <NUM> of the microphone module <NUM> in the embodiment depicted in <FIG>. The audio bus <NUM> serves to receive audio signals from the plurality of microphones <NUM> and to carry or transmit such audio signals along the bus <NUM> to other connected devices. In this way, the audio bus <NUM> is in communication with the plurality of microphones <NUM>. The audio bus <NUM> may comprise a plurality of bus channels <NUM> (see <FIG>) which carry the audio signals of the audio bus <NUM> as described herein. The module processor <NUM> is a local on-board processor which is in communication with the plurality of microphones <NUM> and the audio bus <NUM>. The module processor <NUM> performs a variety of functions in enabling communications among the various components of the microphone module <NUM>, as described herein.

The microphone module <NUM> may further include one or more connectors <NUM>, supported by the housing <NUM> of the module <NUM>. In the embodiment shown in <FIG>, the microphone module <NUM> includes a first connector <NUM> proximate the first end <NUM> of the housing <NUM> and a second connector <NUM> proximate the second end <NUM> of the housing <NUM>. The connectors <NUM>, <NUM> are in electrical communication with the audio bus <NUM> such that when external devices are connected to the connectors <NUM>, <NUM>, audio signals carried by the audio bus <NUM> may be transmitted to and received from such external devices (not shown).

In various embodiments, the connectors <NUM> may be both mechanical and electrical connection devices, as described herein. For example, the connectors <NUM> may both mechanically connect one module <NUM> to another module <NUM> (for example, as described with reference to <FIG>). At the same time, the connectors <NUM> complete electrical connections between connected modules <NUM>,<NUM>, as described in greater detail herein. The connectors <NUM> may take on a variety of different electrical interfaces, including for example, digital parallel/serial interfaces, analog parallel/serial interfaces, and other wired interfaces. Moreover, the connectors <NUM> may be wireless interfaces or connection points whereby electrical signals are transmitted to and received from connected external devices wirelessly. In such case, the wireless connectors <NUM> may be contained completely within the housing <NUM> of the microphone module <NUM> rather than being visible on the exterior of the housing <NUM> as depicted in <FIG>.

The connectors <NUM> permit the microphone module <NUM> to be connected to one or more other microphone modules in serial or "daisy-chained" fashion, with one module's end being connected to the next module, as explained herein. This connectivity supports the ability of the audio bus <NUM> to carry audio from both the microphones <NUM> on board of the microphone module <NUM> as well as audio from any other microphone modules downstream of the module <NUM> and connected to the module <NUM> via the connectors <NUM>. Similarly, the connectors <NUM> allow the audio bus <NUM> to transmit audio signals upstream to any other devices (such as another microphone module) connected via the connectors.

In an embodiment, the module processor <NUM> is a field-programmable gate array, or FPGA device. However, in other embodiments, the module processor <NUM> may take on various other forms of processors capable of controlling inputs and outputs to the module <NUM> and controlling the audio bus <NUM>. For example, the module processor <NUM> could be one of many appropriate microprocessors (MPU) and/or microcontrollers (MCU). The module processor <NUM> could further comprise an application specific integrated circuit (ASIC) or a customized hardware ASIC such as a complex programmable logic device (CPLD). The module processor <NUM> could further comprise a series of digital/analog bus multiplexers/switches to re-configure how inputs and outputs to the module <NUM> are connected.

The microphones <NUM> in the module <NUM> may be any suitable type of transducer that can detect the sound from an audio source and convert the sound to an electrical audio signal. In a preferred embodiment, the microphones <NUM> are micro-electrical mechanical system (MEMS) microphones. In other embodiments, the microphones <NUM> may be condenser microphones, balanced armature microphones, electret microphones, dynamic microphones, and/or other types of microphones.

In certain embodiments, the microphone module <NUM> may be able to achieve better performance across the voice frequency range through the use of MEMS microphones. MEMS microphones can be very low cost and very small sized, which allows a large number of microphones <NUM> to be placed in close proximity in a single microphone array. Thus, given the very small sizes of available MEMS microphones, larger numbers of microphones <NUM> can be included in the module <NUM>, and such greater microphone density provides improved rejection of vibrational noise, as compared to existing arrays. Moreover, the microphone density of the array can permit varying beam width control, whereas existing arrays are limited to a fixed beam width. In yet other embodiments, the microphone module <NUM> can be implemented using alternate transduction schemes (e.g., condenser, balanced armature, etc.), provided the microphone density is maintained.

Further, by using MEMS microphones <NUM> in the array in the module <NUM>, processing of audio signals may be conducted more easily and efficiently. Specifically, because some MEMS microphones produce audio signals in a digital format, the module processor <NUM> need not include analog-to-digital conversion/modulation technologies, which reduces the amount of processing required to mix the audio signals captured by the microphones <NUM>. In addition, the microphone array may be inherently more capable of rejecting vibrational noise due to the fact that MEMS microphones are good pressure transducers but poor mechanical transducers, and have good radio frequency immunity compared to other microphone technologies.

In an embodiment, the microphones <NUM> can be coupled to, or included on, a substrate <NUM> mounted within the housing <NUM> of the module <NUM>. In the case of MEMS microphones, the substrate <NUM> may be one or more printed circuit boards (also referred to herein as "microphone PCB"). For example, in <FIG>, the microphones <NUM> are surface mounted to the microphone PCB <NUM> and included in a single plane. In other embodiments, for example, where the microphones <NUM> are condenser microphones, the substrate <NUM> may be made of carbon-fiber, or other suitable material.

The other components of the module <NUM> may also be supported by or formed within the substrate or PCB <NUM>. For example, the module processor <NUM> may be supported by the PCB, and placed in electrical communication with the microphones <NUM>, the audio bus <NUM> and the connectors <NUM> via electrical paths formed in the PCB <NUM>. The audio bus <NUM>, and the various bus channels <NUM> comprising the audio bus <NUM> may also be formed partially or entirely within or upon the PCB <NUM>. Moreover, the connectors <NUM> may be supported by the PCB <NUM>, or may be integrally formed within or upon the PCB <NUM>.

For example, as seen in <FIG>, the first connector <NUM> at the first end <NUM> of the module <NUM> may comprise an electrical connector comprising a plurality of electrical pads <NUM>. Similarly, the second connector <NUM> at the second end <NUM> of the module <NUM> may comprise an electrical connector comprising a plurality of electrical contacts <NUM>. As is described in reference to <FIG>, when the first end <NUM> of a second module <NUM> is inserted into and coupled with the second end <NUM> of a first module <NUM>, such that their connectors <NUM>, <NUM> are connected, the electrical pads (not shown) of the second module <NUM> come into electrical contact with the electrical contacts <NUM> of the first module <NUM>, completing the electrical connection between the two modules <NUM>,<NUM>. The electrical pads of the second module <NUM> may be similar to the electrical pads <NUM> of the first module <NUM>. In an embodiment, either or both of the electrical pads <NUM> and contacts <NUM> may be formed into the PCB, such as the first connector <NUM> in <FIG>.

In an embodiment, the audio bus <NUM> comprises a time division multiplex bus (or TDM bus). The TDM bus has a plurality of audio channels <NUM>, which in the embodiment shown in <FIG> is eight audio channels <NUM>. In alternative embodiments, greater or fewer audio channels <NUM> may be provided on the audio bus <NUM>, depending on the quantity of microphones <NUM> provided in the module <NUM>, and the applications in which the module <NUM> is contemplated to be used.

Using time division multiplexing, as is known, allows for transmitting and receiving independent signals over a common signal path. In TDM, a plurality of audio signals, or bit streams are transferred appearing simultaneously as sub-channels in one communication channel, but are physically taking turns on the communication channel. Thus, by using a TDM bus as the audio bus <NUM>, the audio bus <NUM> can have fewer audio channels <NUM> than the number of audio inputs. For example, as shown in <FIG> and <FIG>, the TDM audio bus <NUM> has eight audio channels <NUM>, which are in communication with twenty-five (<NUM>) microphones <NUM>, as well as any downstream audio from any additional microphone modules connected via the connectors <NUM>. In the embodiment shown in <FIG> and <FIG>, the TDM bus <NUM> has eight audio channels <NUM> each of which can carry up to twenty-one (<NUM>) microphone signals per channel, for a total of up to <NUM> microphones, allowing as many as six (<NUM>) microphone modules <NUM> to be serially connected or "daisy-chained" together and connected to a single continuous audio bus. In other embodiments, depending on the number of microphones <NUM> present on the module <NUM>, and the configuration of the TDM bus <NUM>, even more modules <NUM> can be serially connected to one another.

A block diagram of the microphone module <NUM> of <FIG> is depicted in <FIG>. As described with reference to <FIG>, the module <NUM> includes a housing <NUM> in which the various components of the module <NUM> are housed. A plurality of microphones 120a-y in the module are in communication with a module processor <NUM>, and an audio bus <NUM>. The audio bus <NUM> is in communication with a pair of connectors <NUM>, which allow the modules <NUM> to be daisy-chained together in serial, end-to-end fashion. The audio bus <NUM> comprises a plurality of audio channels <NUM> over which audio signals from the microphones <NUM> of the module <NUM>, as well as audio signals received from any downstream connected modules via the connectors <NUM>,<NUM> is transmitted.

Turning to <FIG>, a preferred arrangement of microphones <NUM> in a linear array <NUM> for use within a microphone module <NUM> is depicted. The linear array <NUM> comprises twenty-five (<NUM>) microphones 120a-y, which are spaced from one another in the geometry depicted in <FIG>. In this embodiment, the microphones 120a-y are positioned generally along the length (L) of the array. In some embodiments, the microphones 120a-y are spaced and positioned along the array <NUM> in a harmonic nesting fashion to support directional sensitivity to audio of varying frequency bands. Using harmonic nesting techniques, the microphones 120a-y can be used to cover a specific frequency bands within a range of operating frequencies. Harmonic nesting is more fully described in <CIT>, now <CIT>, assigned to Shure Acquisition Holdings, Inc.

In a preferred embodiment, a group of five microphones 120a-e are positioned in close proximity to one another near a first end 122a of the array <NUM> to form a first cluster <NUM> of microphones <NUM>. Similarly, a second group of five microphones 120u-y are positioned in close proximity to one another near a second end 122b of the array <NUM> to form a second cluster <NUM> of microphones <NUM>. In similar fashion, a third cluster <NUM> of microphones <NUM> is formed by a group of nine microphones 120i-q positioned in close proximity to one another near a center 122c of the array <NUM>. This arrangement of clusters <NUM>, <NUM>, <NUM> near the ends 122a,b and center 122c of the array <NUM> supports the ability of the microphone module <NUM> to be "modular" - or connectable in series or daisy-chained fashion with other like microphone modules to form a microphone array of varying or selectable length, as explained herein.

The clusters <NUM>, <NUM>, <NUM> support the ability of the microphone module <NUM> to form steerable microphone beams so as to use the microphones <NUM> of the module <NUM> to transmit desired directional audio and reject undesired audio outside of the microphone beams. Specifically, depending on the frequency range of the audio which is sought to be captured by a microphone array <NUM>, it is beneficial to have a cluster <NUM> at the center 122c of the array <NUM>. However, if the module <NUM> were to only include a cluster <NUM> at the center 122c of the array <NUM>, but not at the ends 122a,b of the array <NUM>, difficulties would arise when connecting the modules <NUM> in serial fashion as contemplated herein.

For example, a system of two connected modules <NUM>, <NUM> is depicted in <FIG>. The module <NUM> may be similar to the module <NUM>, and include a first end <NUM>, a second end <NUM>, and a plurality of microphones 220a-y. When the two modules <NUM>,<NUM> are connected or daisy-chained in serial linear fashion as shown in <FIG>, a composite linear array <NUM>,<NUM> is formed by the arrays <NUM>,<NUM> of the pair of connected modules <NUM>,<NUM>. Since each array <NUM>, <NUM>, includes clusters <NUM>,<NUM>,<NUM>,<NUM> located on the physical ends of the arrays <NUM>,<NUM>, when the arrays <NUM>,<NUM> are combined (through the unification of the two modules <NUM>,<NUM>), the unified array <NUM>,<NUM> maintains a collection of clusters <NUM>,<NUM> at the ends of the system. Moreover, a combined cluster <NUM>,<NUM> remains in the middle of the combined arrays <NUM>,<NUM>, thereby maintaining a cluster of microphones <NUM> in the center of the combined array <NUM>,<NUM>. Therefore, the inclusion of clusters <NUM>,<NUM> at the ends of the module <NUM> as well as a cluster <NUM> in the middle of the module <NUM> supports daisy chaining the modules <NUM>,<NUM> together while maintaining a high level of performance.

The location of the clusters is further demonstrated in a system having three modules, as seen in the system depicted in <FIG>. In <FIG>, a composite array <NUM>,<NUM>,<NUM> is formed by serial connection of three microphone modules <NUM>,<NUM>,<NUM>. The module <NUM> may be similar to the modules <NUM>,<NUM>, and include a housing <NUM>, a first end <NUM>, a second end <NUM>, and a plurality of microphones 320a-y. In such a configuration, the cluster <NUM> of microphones <NUM> in the center 222c of the array <NUM> of the second module <NUM> would also lie in the overall center of the composite array <NUM>,<NUM>,<NUM> formed by the three modules <NUM>,<NUM>,<NUM>. This would be the case for any system having an odd number of modules formed in linear fashion. The module <NUM> may include other clusters <NUM>, <NUM>, <NUM>. The module <NUM> may also include a first connector <NUM> and a second connector <NUM>.

Since the microphone module <NUM> is designed to be used in systems of varying numbers of modules, it is important that the module <NUM> be configured to support connectivity of any number of modules as described above - that is, having a cluster <NUM> of microphones <NUM> in the center 122c of the array <NUM> (as well as end clusters on the array <NUM>) regardless of whether odd or even numbers of modules <NUM> are serially connected or daisy chained in linear fashion. In an embodiment, this is accomplished by the inclusion of the first and second clusters <NUM>,<NUM> at the first and second ends 122a,122b of the array <NUM>. These end clusters <NUM>,<NUM> come together to form a cluster at the center of a composite array formed from even numbered quantities of modules <NUM>.

For example, returning to <FIG>, two microphone modules <NUM>,<NUM> are connected together in serial fashion to form a composite linear array <NUM>,<NUM>. By positioning the first and second modules <NUM>,<NUM> in physical proximity to one another, the second end <NUM> of the housing <NUM> of the first module <NUM> is proximate the first end <NUM> of the housing <NUM> of the second module <NUM>. In this way, the housings <NUM>,<NUM> effectively form a single system of microphones <NUM>,<NUM>, formed by the sets of microphones <NUM>,<NUM> of the individual modules <NUM>,<NUM> forming the system. This further results in the second end 122b of the array <NUM> of the first module <NUM> being adjacent to the first end 222a of the array <NUM> of the second module <NUM>, effectively forming a single, linear composite array <NUM>,<NUM> comprising the two arrays <NUM>,<NUM> of the two modules <NUM>,<NUM>. The inclusion of the end clusters <NUM>,<NUM>,<NUM>,<NUM> on the arrays <NUM>,<NUM> of the modules <NUM>,<NUM> ensures that a cluster of microphones <NUM>,<NUM> is formed when two modules <NUM>,<NUM> are connected in this fashion. Specifically, as seen in <FIG>, the second cluster <NUM> of microphones <NUM> on the first module <NUM> is proximate the first cluster <NUM> of microphones <NUM> of the second module <NUM>, such that the composite array <NUM>,<NUM> now includes a center cluster of microphones <NUM>,<NUM> formed by these two clusters <NUM>,<NUM>. Similarly, in any system including an even number of modules <NUM> connected together in serial, linear fashion, the system will always include a cluster of microphones <NUM> in the center of the composite array <NUM>,<NUM> formed by the modules <NUM>,<NUM> in the system.

Turning to <FIG>, a block diagram of an embodiment of a modular array microphone system <NUM> is depicted. The system <NUM> includes one or more microphone modules <NUM>, such as the modules <NUM>,<NUM>,<NUM> described in reference to <FIG> and <FIG>. In the embodiment shown, the system <NUM> includes three microphone modules <NUM>,<NUM>,<NUM>. The system <NUM> further includes an array processor <NUM> which is in communication with the modules <NUM>,<NUM>,<NUM> of the system <NUM>. The array processor <NUM> acts to control the system <NUM>, and works in conjunction with the module processors <NUM>, <NUM>, <NUM> of the connected modules <NUM>,<NUM>,<NUM>.

In an embodiment, such as the one shown in <FIG>, the system includes a control module <NUM>, which may be a separate piece of hardware from the microphone modules <NUM>,<NUM>,<NUM> in the system <NUM>. The control module <NUM> comprises a housing <NUM> which contains the components of the control module <NUM>. The array processor <NUM> may be a component of the control module <NUM> and located within the control module housing <NUM>. The control module <NUM> may include a connector <NUM> for placing the control module <NUM> in electrical connection with the other components of the system <NUM>, such as the microphone modules <NUM>,<NUM>,<NUM>, for example through the use of an appropriate cable connection.

In alternative embodiments, such as the embodiment shown and described with reference to <FIG>, the array processor <NUM> may be on board of one or more of the microphone modules <NUM>,<NUM>,<NUM>, such that a separate control module <NUM> is unnecessary. In such embodiments, each microphone module <NUM>,<NUM>,<NUM> may include an array processor <NUM>, such that when the modules <NUM>,<NUM>,<NUM> are interconnected as described herein, the on board array processors <NUM> will be in communication with one another via the audio bus <NUM>, or other electrical connections between the modules <NUM>,<NUM>,<NUM>. Once interconnected, one or more of the array processors <NUM> of the system <NUM> may perform the system control and processing functions as described herein with reference to the array processor <NUM>.

In an embodiment, a plurality of modules <NUM>,<NUM>,<NUM> may be connected in serial fashion via their respective connectors <NUM>,<NUM>,<NUM>, and in turn, connected to the array processor <NUM>, via the connector <NUM> on the control module <NUM>, as seen in <FIG>. More specifically, an electrical connection is made from the connector <NUM> of the control module <NUM> to the first connector <NUM> of the first microphone module <NUM>. To "daisy chain" or serially connect the second microphone module <NUM>, an electrical connection is made from the second connector <NUM> of the first module <NUM> to the first connector <NUM> of the second module <NUM>. Similarly, a third microphone module <NUM> can be added to the chain by completing an electrical connection from the second connector <NUM> of the second microphone module <NUM> to the first connector <NUM> of the third module <NUM>. The system <NUM> can be increased to include additional microphone modules <NUM>,<NUM>,<NUM> connected in similar manner using the available connections <NUM>,<NUM>,<NUM> on the modules <NUM>,<NUM>,<NUM>.

Once connected, the array processor <NUM> controls the system <NUM> by interacting with the audio bus <NUM>,<NUM>,<NUM> passing through the connected microphone modules <NUM>,<NUM>,<NUM>. The audio buses <NUM>, <NUM> may be similar to audio bus <NUM> and may comprise a plurality of bus channels <NUM>, <NUM>, respectively, which carry the audio signals of the audio buses <NUM>, <NUM>. In this way, the array processor <NUM> acts as a master controller of the system <NUM>. The module processors <NUM>, <NUM>,<NUM> support the system <NUM> by relaying information to and from the array processor <NUM>, and assisting in configuring the system <NUM> operationally. Once connected, the audio busses <NUM>, <NUM>,<NUM> of the various modules <NUM>,<NUM>,<NUM> work in concert to form a composite audio bus for the system <NUM>.

For example, in an embodiment such as the one shown in <FIG>, once the system <NUM> components are connected and powered up, the module processors <NUM>,<NUM>,<NUM> work in conjunction with the array processor <NUM> to determine and identify the connected components in the system <NUM>. In an embodiment, the system <NUM> self detects, realizes, and shares information about the connected components of the system - including the quantity and connection order of the microphone modules <NUM>,<NUM>,<NUM> in the system <NUM>. Thus, each module processor <NUM>,<NUM>,<NUM> can determine what is connected to the module <NUM>,<NUM>,<NUM> on which it resides, and the interconnected modules <NUM>,<NUM>,<NUM> can share that connection information with one another, and with the array processor <NUM>.

In an embodiment, depicted in <FIG>, for example, the module processors <NUM>,<NUM>,<NUM> can determine the connection configuration of the microphone module <NUM>,<NUM>,<NUM> on which the processor <NUM>,<NUM>,<NUM> resides. In the embodiment shown, each microphone module <NUM>,<NUM>,<NUM> will be detected as being one of five available connection configurations. For example, if the first microphone module <NUM> was not connected to either a control module <NUM> or array processor <NUM>, nor was it connected to any other microphone modules <NUM>,<NUM>, its module processor <NUM> could detect that the microphone module <NUM> was in a "Stand Alone" configuration - and the module <NUM> could be placed in operation in such a configuration. If the microphone module <NUM> was connected to a control module <NUM>, but not to any other microphone modules <NUM>,<NUM>, the module processor <NUM> could detect that it was in a "Single Block with Array Processor" configuration, comprising a system <NUM> of just an array processor <NUM> and one connected module <NUM>.

If the microphone module <NUM> was connected to a control module <NUM>, and at least one other microphone module <NUM>,<NUM>, the module processor <NUM> could detect that it was in a "First Block" configuration (signifying that the module <NUM> was the first in chain of a plurality of modules <NUM>,<NUM>,<NUM> connected to the control module <NUM>). If a microphone module <NUM> was neither the first nor the last module <NUM>,<NUM> in a chain of modules <NUM>,<NUM>,<NUM> connected to a control module <NUM>, the module processor <NUM> would detect that the microphone module <NUM> was in a "Middle Block" configuration. Finally, if a microphone module <NUM> was the last module <NUM> in a chain of modules <NUM>,<NUM>,<NUM> connected to a control module <NUM>, the module processor <NUM> would detect that the microphone module <NUM> was in a "Last Block" configuration. Thus, the selfdetection capabilities of the system <NUM> allow each module <NUM>,<NUM>,<NUM> in the system to determine which of the five configurations it is in (Stand Alone, Single Block with Array Processor, First Block, Middle Block, or Last Block), and to share such configuration information with the other modules <NUM>,<NUM>,<NUM> of the system <NUM>, as well as the array processor <NUM>, to configure the system <NUM>.

Through interactions between one or more of the array processor <NUM> and the microphone module processors <NUM>,<NUM>,<NUM>, the system <NUM> is intelligent so as to sense and determine its configuration. For example, in the three module system depicted in <FIG>, after the self detection processes executes and completes as described above, the array processor <NUM> and each of the module processors <NUM>,<NUM>,<NUM> will know the quantity of connected microphone modules <NUM>,<NUM>,<NUM> (in this case three), and a connection order of the connected microphone modules <NUM>,<NUM>,<NUM> (in this case, the first module <NUM> is connected first, the second module <NUM> is connected second, and the third module <NUM> is connected third). One or more of the processors <NUM>,<NUM>,<NUM>,<NUM> will configure the modules <NUM>,<NUM>,<NUM> so that the system <NUM> places the first module <NUM> in "First Block" mode or configuration, places the second module <NUM> in a "Middle Block" mode, and places the third module <NUM> in a "Last Block" mode.

These configuration steps set up the system <NUM> to work in a unified manner, and allow the module processors <NUM>,<NUM>,<NUM> to configure each module <NUM>,<NUM>,<NUM> to properly populate the audio bus <NUM>,<NUM>,<NUM> with audio signals from both the on board microphones <NUM>,<NUM>,<NUM> of the modules <NUM>,<NUM>,<NUM> as well as any audio from downstream modules <NUM>,<NUM>. For example, the third module <NUM>, being in "Last Block" mode, knows that it is not going to receive any audio signals from any downstream modules, since no additional modules are connected to it. Therefore, the system <NUM> configures the audio bus <NUM> so as to populate the audio bus <NUM> with audio signals from its onboard microphones <NUM>. The second module <NUM>, being in "Middle Block" mode, knows that it is receiving audio signals from one or more downstream modules (in this case the third module <NUM>). Therefore, the system <NUM> configures the audio bus <NUM> so as to populate the audio bus <NUM> with audio signals from both its onboard microphones <NUM> as well as audio signals from connected downstream modules, such as the third module <NUM>. Similarly, the first module <NUM>, being in "First Block" mode, knows that it is receiving audio signals from one or more downstream modules (in this case the second and third modules <NUM>,<NUM>). Therefore, the system <NUM> configures the audio bus <NUM> so as to populate the audio bus <NUM> with audio signals from both the onboard microphones <NUM> as well as audio signals from connected downstream modules, such as the second and third modules <NUM>,<NUM>.

In this way, the system <NUM>, across the control module <NUM> and connected microphone modules <NUM>,<NUM>,<NUM>, comprises a composite audio bus formed from the audio busses <NUM>,<NUM>,<NUM> of the connected microphone modules <NUM>,<NUM>,<NUM>. The composite audio bus carries all of the audio signals from the microphones <NUM>,<NUM>,<NUM> of the connected microphone modules <NUM>,<NUM>,<NUM>, and passes those audio signals to the control module <NUM> where they can be processed and further transmitted by the array processor <NUM>. Thus, in embodiments, the array processor <NUM> is also in communication with an output channel to transmit audio received by the array processor <NUM> via the composite audio bus <NUM>,<NUM>,<NUM>. For example, the array processor <NUM> may be in communication with an output channel via a connection in the control module <NUM> that allows outbound audio to be further transmitted to an output device. For example, the output device may be one or more speakers for transmitting the sound, an audio amplifier, a telecommunications device for transmitting sound, etc. In a conferencing environment, the output channel may connect to local loudspeakers mounted in the environment for sound reinforcement. Or the output channel may connect to a teleconferencing bridge for transmitting audio to remote locations, for example, other users connected to a conference call.

As described herein, the modular aspect of the microphone modules <NUM> allow creation and configuration of various systems <NUM> using the modules <NUM> as "building blocks" for the system <NUM>. In this way, the system <NUM> uses the modules <NUM> to form an "array of array microphones" by using the modular nature of each of the microphone modules <NUM>,<NUM>,<NUM> to form a customized microphone array, which depends on the number of the microphone modules <NUM>,<NUM>,<NUM> which are connected together to form the system <NUM>. The array processor <NUM> can then use audio signals from any and all of the microphones <NUM>,<NUM>,<NUM> in the system to perform flexible beam forming calculations, and form steerable microphone beams as described further herein.

Turning to <FIG>, an example embodiment of the system <NUM> of <FIG> is depicted. As described, the three microphone modules <NUM>,<NUM>,<NUM> are connected and daisy chained together to form a single microphone array. The first module <NUM> is connected to the control module <NUM> via an electrical cable which connects the control module connector <NUM> to the first connector <NUM> of the first module <NUM>. It should be understood that the electrical cable connecting the control module connector <NUM> and the first connector <NUM> need not directly connect the two connectors <NUM>,<NUM> - but rather, one or more intermediate pieces of hardware, processing units, or cabling may exist in such connection, so long as signals can pass to and from the array processor <NUM> and the first module <NUM> such that the two are in communication.

The second connector <NUM> of the first module <NUM> is connected to the first connector <NUM> of the second module. Similarly, the second connector <NUM> of the second module <NUM> is connected to the first connector <NUM> of the third module <NUM>. Thus, in the embodiment shown in <FIG>, the modules <NUM>,<NUM>,<NUM> are connected mechanically and electrically to form a single array comprised of the three interconnected modules <NUM>,<NUM>,<NUM>.

In an alternative embodiment depicted in <FIG>, the various modules <NUM>,<NUM>,<NUM> of the system <NUM> may be electrically connected by various wires or cables <NUM>. Thus, a first cable may be used to connect the second connector <NUM> of the first module <NUM> to the first connector <NUM> of the second module <NUM>. Similarly, a second cable may be used to connect the second connector <NUM> of the second module <NUM> to the first connector <NUM> of the third module <NUM>. The use of connecting cables, as shown, provides greater flexibility in mounting the modules <NUM>,<NUM>,<NUM> since in this embodiment, the modules <NUM>,<NUM>,<NUM> are not mechanically connected to one another, but rather are only electrically connected via the cables between their respective connectors <NUM>,<NUM>,<NUM>. Thus, by using connecting cables of various lengths, the physical spacing of the modules <NUM>,<NUM>,<NUM> of the system <NUM> can be customized and controlled in the environment in which the system <NUM> is deployed. In these ways, the ability to connect or daisy chain the modules <NUM>,<NUM>,<NUM> allows designers and installers of such systems <NUM> to create custom length microphone arrays by employing different numbers of microphone modules <NUM>,<NUM>,<NUM> connecting them in the ways described herein.

Additionally, in the embodiment shown in <FIG>, the array processor(s) <NUM> which control the system <NUM> may be included on board of the various modules <NUM>,<NUM>,<NUM> of the system <NUM> (as opposed to in a separate hardware control module <NUM> like other embodiments described herein). Thus, in <FIG>, each of the microphone modules <NUM>,<NUM>,<NUM> includes an array processor 60a,60b,60c. Turning to the first module <NUM>, the array processor 60a is in communication with the other components of the module <NUM>, including the module processor <NUM>, the audio bus <NUM>, the connectors, <NUM>,<NUM>,<NUM>, and the microphones <NUM>. The other modules <NUM>,<NUM> are similarly configured. Thus, the various array processor 60a,60b,60c may work together to perform system level control and processing in a manner similar to the array processor <NUM> in <FIG>. In the embodiment in <FIG>, the system <NUM> may configure itself such that one of the array processors 60a,60b,60c is a "master" array processor, and controls the system level processing of the system <NUM>. Alternatively, a plurality, or all of the array processors 60a,60b,60c may handle the system level processing demands, as described herein.

In an embodiment of the invention, the system <NUM> must compensate for time shifts in the various audio signals received by the array processor <NUM> via the composite audio bus <NUM>,<NUM>,<NUM>. Thus, because the various microphones <NUM>,<NUM>,<NUM> of the various connected microphone modules <NUM>,<NUM>,<NUM> of a system <NUM> are receiving audio at the same time, but transmitting such audio to the array processor <NUM> over differing lengths of the audio bus <NUM>,<NUM>,<NUM>, the audio signals received by the microphones <NUM>,<NUM>,<NUM> may arrive at the array processor <NUM> with varying latencies and delays. Thus, the system <NUM> needs to account for the varying latencies of the received audio signals from the microphones <NUM>,<NUM>,<NUM> of the modules <NUM>,<NUM>,<NUM> in the system <NUM>. In an embodiment, the array processor <NUM> performs a time alignment process to synchronize the audio received from the various microphones <NUM>,<NUM>,<NUM> of the modules <NUM>,<NUM>,<NUM>. This prevents undesirable effects such as echo or noise as the array processor <NUM> further transmits the audio signals of the system <NUM> to output devices. The time alignment process, or synchronization, can be performed by the array processor <NUM>, on a system level. Alternatively, the time alignment process can be performed by one or more of the module processors <NUM>,<NUM>,<NUM> of the modules <NUM>,<NUM>,<NUM> of the system. Or the processors <NUM>,<NUM>,<NUM>,<NUM> may time align the audio signals by working cooperatively. In an embodiment, the system <NUM> may encode the audio signals with time stamp information when the audio signals are transmitted via the audio bus <NUM>,<NUM>,<NUM>, and use such time stamp information to time align the audio signals.

Turning to <FIG>, an alternative embodiment of a system <NUM> including a plurality of microphone modules <NUM> is depicted. In this embodiment, one or more modules <NUM> are connected in banks 70a,b,c,d, with each bank 70a,b,c,d being connected to a central control module <NUM>, specifically via the connector <NUM> of the module <NUM>. It should be understood that the connector <NUM> may be a single electrical connector or connection point, or alternatively may comprise a plurality of connectors or connection points used to connect the various banks 70a,b,c,d as described herein.

As seen in <FIG>, in a particular application in a conferencing environment, four banks 70a,b,c,d of microphone modules <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM> are connected around the periphery of a wall mounted television <NUM>. The first bank 70a is mounted above the television <NUM>, and comprises six modules 100a,200a,300a,400a,500a,600a, connected in a daisy chained fashion as described herein. The first module 100a is connected to the control module <NUM> as described with reference to <FIG>. Similarly, a second bank 70b of modules is positioned along a right edge of the television <NUM>. The second bank 70b comprises two modules 100b,200b connected in a daisy chained fashion with the first module 100b connected to the control module <NUM>. A third bank 70c of modules is mounted along a bottom edge of the television <NUM>. The third bank 70c comprises six modules 100c,200c,300c,400c,500c,600c, with the first module 100c connected to the control module <NUM>. Finally, a fourth bank 70d of modules is positioned along a left edge of the television <NUM>. The fourth bank 70d comprises two microphone modules 100d,200d connected in a daisy chained fashion with the first module 100d connected to the control module <NUM>.

Therefore, the system <NUM> depicted in <FIG> comprises a plurality of banks 70a,b,c,d connected to a central control module <NUM> having an array processor <NUM>. Each of the banks 70a,b,c,d comprises a plurality of modules <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>. All of the modules <NUM> of the various banks 70a,b,c,d are under the control of the central control module <NUM> as described herein. Therefore, the flexibility of the system <NUM> is a valuable asset to designers and installers of such systems <NUM> in that the length of the various banks 70a,b,c,d can be customized with differing numbers of modules <NUM> in each bank 70a,b,c,d, and any of number of banks 70a,b,c,d can be utilized to create systems <NUM> having appropriate placement of microphone arrays in a variety of environments where sound is to be captured and transmitted by the system <NUM>. The various arrangements of modules <NUM> in banks 70a,b,c,d as depicted in <FIG> allows for highly customizable solutions to be provided in the field with quantities of a single variety of array module <NUM>, making such systems <NUM> desirable for ease of installation and design. Thus, the system <NUM> can be configured to comprise one chain of serially connected modules <NUM>,<NUM>,<NUM> - such as the system depicted in <FIG>. Or the system <NUM> can be configured to comprise multiple chains of serially connected modules, arranged in banks 70a,b,c,d, such as the system <NUM> depicted in <FIG>.

Systems <NUM> such as the one depicted in <FIG> and described in relation to the other figures, may be configured, controlled and utilized to form microphone pick up patterns or "beams" to optimize directional sensitivity of the system <NUM>, as described herein. For example, turning to <FIG>, a variety of steerable beams 90a-g may be formed using the microphones of the various modules <NUM>,<NUM>,<NUM> of the system <NUM>. In <FIG>, such a system <NUM> includes three microphone modules <NUM>,<NUM>,<NUM> connected in a daisy chained fashion as described herein. Under the control of a connected control module (not shown), the microphone modules <NUM>,<NUM>,<NUM> may be used to form a variety of beams 90a-g having various shapes, sizes, and directional pick up patterns. For example, as seen in <FIG>, a first beam 90a may be formed by the system <NUM> using only the first module <NUM>, and extending in an oval shaped fashion in a direction transverse to the module <NUM>. Simultaneously, a second beam 90b may be formed using the second and third modules <NUM>,<NUM>, and extending in a wider oval shaped manner, also transverse to the length of the modules <NUM>,<NUM>. In this way, the control module <NUM> can operate the modules <NUM>,<NUM>,<NUM> of the system <NUM> independently or in concert to form a variety of beams 90a,b. The beams can be entirely within a single module <NUM>, such as beam 90a. Or alternatively the beams can be across multiple modules <NUM>,<NUM>, such as beam 90b.

Turning to <FIG>, another embodiment of the system <NUM> of <FIG> is depicted, in which a plurality of beams 90c,d are formed across a plurality of modules <NUM>,<NUM>,<NUM>. In this embodiment, a first beam 90c is formed across a first module <NUM> and a portion of a second module <NUM>. A second beam 90d is formed across a portion of the second module <NUM> and a third module <NUM>. Thus, the control module <NUM> uses three microphone modules <NUM>,<NUM>,<NUM> to create a pair of symmetrical beams 90c,d which are oval shaped pick up patterns extending from and transverse to the modules <NUM>,<NUM>,<NUM>.

In yet another embodiment depicted in <FIG>, the system <NUM> of <FIG> is configured to create overlapping beams 90f,g. In this embodiment, a first beam 90f is formed across a portion of a first module <NUM> and a portion of a second module <NUM>. A second beam <NUM> is formed across a portion of the second module <NUM> and a portion of a third module <NUM>. Both beams 90f,g are oval shaped pick up patterns extending from and transverse to the modules <NUM>,<NUM>,<NUM>. However, in this embodiment, the beams 90f,g overlap to achieve the desired pick up pattern depicted in <FIG>.

Therefore, the control module <NUM> can use the microphones <NUM> of the first module <NUM>, the microphones <NUM> of the second module <NUM> and the microphones <NUM> of the third module <NUM> to create independent beams 90a-g which can be created entirely on one module <NUM>,<NUM>,<NUM>, extend across multiple modules <NUM>,<NUM>,<NUM> and can be distinct and separate from one another (such as the beams 90a-d in <FIG>) or can overlap (such as the beams 90f,g in <FIG>). In this way, the microphones of the various modules <NUM>,<NUM>,<NUM> can be used to form beams 90a-g of a variety of shapes, sizes, and directions. Moreover, audio signals received by a microphone <NUM> aboard one of the modules <NUM> may be utilized to form multiple beams 90a-g. Thus, each microphone <NUM>, <NUM>, <NUM> of the system <NUM> can participate in forming multiple beams 90a-g such as the microphones <NUM> of the second module <NUM> depicted in <FIG>, which participate in forming both beams 90f,g shown.

Turning to <FIG>, another application of a system <NUM> according to the embodiments described herein is depicted. In the depicted application, the system <NUM> is deployed in a conference room setting, which includes a conference table <NUM> and a plurality of sound sources, in this case humans talking, or "talkers" 84a-f, positioned around the table <NUM>. In the configuration shown, six talkers 84a-f are positioned around the conference table <NUM>, with three talkers 84a,b,c on one side of the table <NUM> and three talkers 84d,e,f on the opposite side of the table <NUM>. A system <NUM> is deployed in the environment which includes six microphone modules <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM> connected to a control module (not shown). The six modules <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM> are connected in a daisy chained fashion to create a microphone array, which in this case is positioned on a top surface of the conference table <NUM>.

The control module (not shown) has configured the system <NUM> to create a plurality of beams <NUM>,i,j,k for the purposes of picking up the sounds and audio created by the talkers 84a-f. As depicted in <FIG>, three high frequency beams <NUM>,i,j have been created by the system <NUM>, each of the beams <NUM>,i,j being a similarly sized and shaped oval pick up pattern extending transversely from the modules <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>. The first high frequency beam <NUM> is created across the first and second modules <NUM>,<NUM>, extending in opposite directions from the modules <NUM>,<NUM> so as to create directional pick up patterns to optimally pick up audio from two talkers 84a,d seated across from each other proximate a left end of the conference table <NUM>. The second high frequency beam 90i is created across the third and fourth modules <NUM>,<NUM>, extending in opposite directions from the modules <NUM>,<NUM> so as to create directional pick up patterns to optimally pick up audio from two talkers 84b,e seated across from each other proximate a center of the conference table <NUM>. Similarly, the third high frequency beam 90j is created across the fifth and sixth modules <NUM>,<NUM>, extending in opposite directions from the modules <NUM>,<NUM> so as to create directional pick up patters to optimally pick up audio from two talkers 84c,f seated across from each other proximate a right end of the conference table <NUM>.

The system <NUM> further includes a low frequency beam <NUM>, which is created across all six of the modules <NUM>-<NUM>, extending from the first module <NUM> to the last module <NUM>. Like the high frequency beams <NUM>,i,j, the low frequency beam <NUM> extends in opposite directions from the modules <NUM>-<NUM> so as to create directional pick up patterns to optimally pick up low frequency components of all six of the talkers 84a-f, seated on opposing sides of the conference table <NUM>. Therefore, the system <NUM> may create different beams <NUM>,i,j,k for different frequency ranges, using different subsets or portions of the modules <NUM>-<NUM> used to create the system. In an embodiment, low frequency audio sources are more effectively captured by physically longer arrays, such that it is optimal to use the entire length of the system of modules <NUM>-<NUM> to capture such low frequency sources. Conversely, it may be more effective to capture higher frequency audio sources by shorter arrays, such that it is optimal to use microphones across a subset of the available modules <NUM>-<NUM> to create a beam (such as beam <NUM> which is created across the first two modules <NUM>,<NUM>).

In this way, the system <NUM> uses the microphones of the various connected modules <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM> to create beams <NUM>,i,j,k which are configured for optimal pick up of audio in the environment. In the system <NUM> of <FIG>, six modules <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM> are used to create four beams <NUM>,i,j,k to capture audio signals from six talkers 84a-f seated around a conference table. However, given the efficient configurability of the system <NUM>, the control module could quickly and easily reconfigure the system <NUM> to create greater or fewer beams <NUM>,i,j,k, or to change the shape and positioning of beams <NUM>,i,j,k to accommodate changes in the environment, without having to disconnect, move, or disturb the hardware arrangement of the modules <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>. This flexibility is one of many advantages provided by such a system <NUM> using connectible microphone modules <NUM>. Moreover, the system <NUM> can move, adjust or "steer" the beams <NUM>,i,j,k such that the axis of the beams <NUM>,i,j,k is better aligned with the intended sound source so as to more optimally capture audio coming from the source.

As can be understood from the example embodiments described herein, various systems <NUM> using a plurality of modules <NUM>,<NUM>,<NUM>, can be created and deployed in a variety of environments. Thus, in a system <NUM> including "N" modules <NUM>, the array processor <NUM> may select from the available microphones <NUM> across the various N modules <NUM> in selecting audio signals to utilize for creating and forming the steerable beams <NUM>a-k used by the system <NUM>. In an embodiment, the microphones <NUM> which the system <NUM> selects, and modules <NUM> upon which those microphones <NUM> are located are based upon the number of modules <NUM>, or "N", of the system <NUM>. Therefore, for example, a system <NUM> having three modules <NUM> may utilize different microphones <NUM> across the modules to form an optimal beam to pick up directional sound from a source, than in a system <NUM> having six modules <NUM>. Therefore, in an embodiment, the array processor <NUM> determines the number of modules <NUM> available to the system <NUM>, or "N", as well as the number of microphones <NUM>, and uses this data in beam forming as described herein. In other embodiments, other data may be collected from the system <NUM> and used in configuration of the number, size, and shape of the microphone beams.

The systems <NUM> described herein generally refer to pick up of audio from acoustic sources within the audible spectrum (approximately <NUM> - <NUM>). However, the systems <NUM> described herein are not limited to acoustic signals within the audible spectrum and can be configured to pick up acoustic sources of varying frequencies. Therefore, as used herein, "audio sources" and "audio bus" should not be construed to be limited in any way with respect to the frequency of such signals - rather such terms are intended to include detection of all ranges of acoustic signals. Therefore, the microphones <NUM> of the various modules <NUM> and systems <NUM> described herein can be any variety of transducers, including transducers that are capable of detecting acoustic signals outside of the audible frequency range - for example, ultrasound waves. In manners similar to those described herein, the systems <NUM> and modules <NUM> of the present disclosure can be configured to detect such other acoustic signals and to process and transmit them in a similar manner to the audio signals described herein.

In various embodiments, the modules <NUM> themselves, including the general shape and configuration of the modules <NUM> and their housings <NUM> may take on a variety of shapes. For example, the modules <NUM> may be elongated and linear such as some of the embodiments shown herein. Alternatively, the modules <NUM> may be arced, circular, square, rectangular, cross-shaped, intersecting, parallel or other arrangements. The modules <NUM> may include more than two connectors on them, so that they may be mechanically connected to one another to form systems <NUM> of modules <NUM> of varying shapes, sizes and configurations. For example, the modules <NUM> may be connected together to extend in two dimensions (such as a cross-shaped arrangement, or rectangular arrangement of modules), or in three dimensions (such as modules connected in a cube, sphere, or other three dimensional shape). In an embodiment, a system <NUM> may include three dimensional configuration of modules <NUM> interconnected to one another so as to form an object which may be placed in an environment, for example, by suspending the system from the ceiling in a "chandelier like" fashion.

In alternative embodiments, it should be understood that other audio bus configurations may be utilized. For example, a system of modules may be used where the modules are mechanically interconnected to form an array of modules, without the audio being passed "upstream" through each module, but rather using a different audio signal routing. In one such embodiment, audio signals from each module in the system can be routed to a central point or hub, and then from that central point, upstream to the array processor. Such a configuration may be referred to as a "hub and spoke" configuration, or "star topology. " In other embodiments, a plurality of hubs may be used, whereby each hub collects audio signals from a plurality of connected modules, and passes the combined audio up to one or more array processors. Other configurations of audio routing are possible as well.

Any process descriptions or blocks in figures should be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process, and alternate implementations are included within the scope of the embodiments of the invention in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those having ordinary skill in the art.

Claim 1:
A modular array microphone system (<NUM>) comprising:
an array processor (<NUM>);
an audio bus (<NUM>, <NUM>, <NUM>); and
N microphone modules (<NUM>, <NUM>, <NUM>), where N is at least <NUM>, wherein each of the N microphone modules (<NUM>, <NUM>, <NUM>) comprises:
a housing (<NUM>, <NUM>, <NUM>);
a plurality of microphones (120a-y, 220a-y, 320a-y) supported by the housing (<NUM>, <NUM>, <NUM>); and
a module processor (<NUM>, <NUM>, <NUM>) in communication with the plurality of microphones (120a-y, 220a-y, 320a-y) and the audio bus (<NUM>, <NUM>, <NUM>);
wherein the audio bus (<NUM>, <NUM>, <NUM>) connects the array processor (<NUM>) and the N microphone modules (<NUM>, <NUM>, <NUM>) such that the plurality of microphones (120a-y, 220ay, 320a-y) in each of the N microphone modules (<NUM>, <NUM>, <NUM>) is in communication with the array processor (<NUM>);
wherein one or more of the array processor (<NUM>) and the module processors (<NUM>, <NUM>, <NUM>) in the N microphone modules (<NUM>, <NUM>, <NUM>) are configured to:
detect a quantity and a connection order of the N microphone modules (<NUM>, <NUM>, <NUM>); and
configure the audio bus (<NUM>, <NUM>, <NUM>) to route audio signals from the plurality of microphones (120a-y, 220a-y, 320a-y) in each of the N microphone modules (<NUM>, <NUM>, <NUM>) to the array processor (<NUM>).