Abstract:
Modern electronic devices are becoming smaller while the need to critically locate acoustic sensors or transducers, e.g., microphones, is increasing in order to provide improved intelligibility in adverse environments. The acoustic transducers can be used in arrays with their outputs processed in beam forming and noise cancellation algorithms. The use and creation of features on the surface of a small package to deal with the problem of achieving high performance solutions in a limited space are disclosed herein. For example, embodiments of electronic communication devices ( 10 ) include acoustic transducers ( 26 ) integrated with other features such as a volume control ( 34, 50 ), an antenna ( 87, 260, 280 ), an adapter ( 300 ) which can be coupled to an input/output jack ( 90 ) and an accessory connector, or a projection ( 98 ).

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Statement of the Technical Field 
         [0002]    The inventive arrangements in this patent disclosure relate to electronic devices, such as hand-held radios, that require one or more microphones or other types of acoustic transducers. 
         [0003]    2. Description of the Related Art 
         [0004]    The components of many electronic communication devices, such as hand-held land mobile radios, are densely packaged in order minimize their overall dimensions, while maximizing the performance and functionality thereof. The number of suitable mounting locations for acoustic transducers, such as microphones, on such devices is usually limited. In particular, an acoustic transducer generally needs to be mounted on an external face of the device. Moreover, the suitability of a particular face for use in accommodating an acoustic transducer is dependent upon whether the face will be covered during normal use of the device. For example, a face that will be covered by a holster, a coat pocket, or a mounting bracket during normal use of the device is generally an unsuitable location for mounting an acoustic transducer. 
         [0005]    Also, technological developments such as active noise cancellation, sound localization, and sound isolation can necessitate the use of arrays of two or more acoustic transducers. The relative locations and the orientations of the acoustic transducers used in such applications are often critical factors in achieving the desired performance from the acoustic-transducer system. The use of multiple acoustic transducers, which need to be positioned in specific relative locations and orientations, is at odds with the limited availability of suitable mounting locations for acoustic transducers on many electronic communication devices. 
       SUMMARY OF THE INVENTION 
       [0006]    Embodiments of electronic devices include a shell; a rotary control; and an acoustic transducer co-located with the rotary transducer on the shell. 
         [0007]    Further embodiments of electronic communication devices include a shell; and an input device mounted on or extending through the shell. The input device includes a first portion having a control configured to generate an output that causes a response in a component of the electronic communication device. The input device also includes a second portion mounted on or coaxially with the first portion and comprising an acoustic transducer. 
         [0008]    In accordance with a further aspect of the claimed inventive concepts, input devices include a first portion having a rotary control configured to generate an electrical output responsive to a rotational input thereto; and a knob mounted on the rotary control and configured to provide the rotational input to the rotary control. The embodiments further include a second portion mounted on or co-axially with the first portion and comprising an acoustic transducer; and a rotating platform having a base and a carousel configured to rotate in relation to the base and the rotary control. The acoustic transducer is configured to rotate with the carousel. The acoustic transducer can be configured to be non-rotatable in relation to the carousel in alternative embodiments. 
         [0009]    In accordance with a further aspect of the claimed inventive concepts, embodiments of radios include a shell, and an input device. The input device includes a first portion having a rotary control configured to generate an electrical output responsive to a rotational input thereto; and a knob mounted on the rotary control and configured to provide the rotational input to the rotary control. The input device also includes a second portion mounted on or co-axially with the first portion. The second portion includes an acoustic transducer, and a rotating platform having a base and a carousel configured to rotate in relation to the base and the rotary control. The acoustic transducer is configured to rotate with the carousel. The radios may include a speaker mounted on or within the shell, and an amplifier communicatively coupled to the first portion of the input device and the speaker. The amplifier is operable to generate an electrical output that drives the speaker in response to an electrical output of the first portion of the input device. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    Embodiments will be described with reference to the following drawing figures, in which like numerals represent like items throughout the figures and in which: 
           [0011]      FIG. 1  is a perspective view of a radio having an integrated volume control and microphone device; 
           [0012]      FIG. 2  is a magnified side view of the area designated “A” in  FIG. 1 ; 
           [0013]      FIG. 3  is a magnified side view of the area designated “A” in  FIG. 1 , depicting a knob of the integrated volume control and microphone device in cross section; 
           [0014]      FIG. 4  is a magnified side view of the area designated “B” in  FIG. 2 , depicting a rotating platform of the integrated volume control and microphone device in partial cut-away; 
           [0015]      FIG. 5  is a schematic illustration of various electrical components of the radio and the integrated volume control and microphone device shown in  FIGS. 1-4 ; 
           [0016]      FIG. 6  is a side view of an alternative embodiment of the integrated volume control and microphone device shown in  FIGS. 1-5 , depicting a knob of the alternative embodiment in cross section; 
           [0017]      FIG. 7  is a perspective view of the radio shown in  FIG. 1 , equipped with an antenna having an integrated microphone in lieu of volume control and microphone device shown in  FIGS. 1-5 ; 
           [0018]      FIG. 8  is a magnified view of the area designated “C” in  FIG. 7 ; 
           [0019]      FIG. 9  is a side view of another embodiment of an antenna having an integrated microphone; 
           [0020]      FIG. 10  is a perspective view of the radio shown in  FIG. 1 , equipped with another alternative embodiment of the integrated volume control and microphone device shown in  FIGS. 1-5  in the form of an integrated collar and microphone; 
           [0021]      FIG. 11  is a magnified side view of the area designated “D” in  FIG. 10 , depicting the integrated collar and microphone in an uninstalled condition; 
           [0022]      FIG. 12  is a perspective view of the radio shown in  FIG. 1 , equipped with an alternative embodiment of the integrated collar and microphone shown in  FIGS. 10 and 11 ; 
           [0023]      FIG. 13  is a schematic illustration of various electrical components of the integrated collar and microphone shown in  FIG. 12 ; 
           [0024]      FIG. 14  is a perspective view of the radio shown in  FIG. 1 , equipped with another alternative embodiment of the integrated collar and microphone shown in  FIGS. 10 and 11 ; 
           [0025]      FIG. 15  is a perspective view of the radio shown in  FIG. 1 , equipped with another alternative embodiment of the integrated volume control and microphone device shown in  FIGS. 1-5  in the form of an integrated input/output jack and microphone; and 
           [0026]      FIG. 16  is a perspective view of the radio shown in  FIG. 1 , equipped with another alternative embodiment of the integrated volume control and microphone device shown in  FIGS. 1-5  in the form of an integrated projection and microphone. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    The invention is described with reference to the attached figures. The figures are not drawn to scale and they are provided merely to illustrate the instant invention. Several aspects of the invention are described below with reference to example applications for illustration. It should be understood that numerous specific details, relationships, and methods are set forth to provide a full understanding of the invention. One having ordinary skill in the relevant art, however, will readily recognize that the invention can be practiced without one or more of the specific details or with other methods. In other instances, well-known structures or operation are not shown in detail to avoid obscuring the invention. The invention is not limited by the illustrated ordering of acts or events, as some acts may occur in different orders and/or concurrently with other acts or events. Furthermore, not all illustrated acts or events are required to implement a methodology in accordance with the invention. 
         [0028]      FIGS. 1-5  depict a portable electronic communication device in the form of a hand-held transceiver or radio  10 . The radio  10  can be configured, for example, as a land mobile radio. The radio  10  comprises a housing or shell  11  formed from an impact-resistant material such as high-impact plastic, and a speaker  14  mounted within the shell  11  as shown in  FIG. 1 . 
         [0029]    As depicted in  FIG. 5 , the radio  10  also includes a transmit and receive module  80  configured to facilitate the transmission and reception of radio frequency (RF) signals; a processor  82 ; a transmit/receive antenna jack  84  and antenna  87 ; a global positioning system (GPS) antenna  85 ; a power supply  86 ; input/output circuitry  88 ; a GPS module  89 ; an input/output jack  90  that is configured to mate with an accessory connector (not shown); a display  92 ; a keypad  94 ; a front microphone  96 ; a codec  97 ; and a bus  44  that facilitates communication between components. It should be noted that the schematic illustration of  FIG. 5  is not intended to be a complete depiction of all of the electrical and electronic components of the radio  10 . 
         [0030]    The radio  10  also includes an input device in the form of an integrated volume control and microphone device  12 . The device  12  is mounted on a top surface  20  of the shell  11  as depicted in  FIG. 1 , and includes a first portion  22  and a second portion  24  as shown in  FIGS. 2 and 3 . Alternatively, the device  12  can be mounted on structure, such as an internal chassis for frame, located within the shell  11 , as opposed to being mounted on the shell  11  itself. In such applications, the device  12  can extend through the shell  11  via an opening formed therein. The first and second portions  22 ,  24  are co-located in relation to the shell  11 , i.e., the first and second portions  22 ,  24  are positioned over the same location on the shell  11  or, alternatively, are positioned over the same opening in the shell  11 . 
         [0031]    The first portion  22  facilitates control of the volume of the speaker  14 . The second portion  24  comprises an acoustic transducer in the form of a microphone  26  that facilitates voice and other audio inputs to the radio  10 . The second portion  24  of the device  12  is configured so that the microphone  26  can be rotated independently in relation to the first portion  22  and the shell  11 . The microphone  26  can thus be positioned in an optimum orientation in relation to a sound source being picked-up or transduced, by the microphone  26 . The device  12  is described in connection with a hand-held land mobile radio  10  for exemplary purposed only. The device  12 , and alternative embodiments thereof, can be used as part of other types of mobile and non-mobile electronic devices. 
         [0032]    The use of a microphone  12  as the acoustic transducer on the device  12  is disclosed for exemplary purposes only. Other types of acoustic transducers, such as optical, ultrasonic, and vibration sensors, can be used in the alternative. Also, alternative embodiments of the radio  10  can be equipped with a second microphone. The microphone  12  and the secondary microphone can be used, for example, as primary and secondary microphones (or vice versa) for the purpose of noise cancellation. 
         [0033]    The first portion  22  of the device  12  comprises a rotary control in the form of a rotary encoder  34 . The rotary encoder  34  is a mechanical absolute rotary encoder. Other types of position sensors, such as optical rotary encoders, can be used in the alternative. The rotary encoder  34  generates an electrical output representative of the user-selected volume setting for the speaker  14 . 
         [0034]    The rotary encoder  34  includes a cylindrical casing  40  and a spindle  42 , as illustrated in  FIGS. 2 and 3 . The rotary encoder  34  also includes a plurality of electrical contacts  41  depicted in phantom in  FIG. 3 . The contacts  41  are fixed to an interior surface of the casing  40 , and extend radially inward. The contacts  41  have different respective lengths. The casing  40  is securely mounted on the top surface  20  of the shell  11  by a suitable means such as fasteners. A first portion of the spindle  42 , shown in phantom in  FIG. 3 , is located within the casing  40 , and a second portion of the spindle  42  protrudes from the casing  40 . 
         [0035]    The rotary encoder  34  also includes a disc  38 , depicted in phantom in  FIG. 3 . (not shown). The disc  38  has an electrically-insulative inner circumferential portion  39   a  that is fixed to a bottom end of the spindle  42 , and an electrically-conductive outer circumferential portion  39   b.  The outer circumferential portion  39   b  has a series of cut-outs (not visible in  FIG. 3 ) of different depths, or radial dimensions, formed along its outer periphery. The disc  38  is mounted for rotation within the casing  40 , and the outer circumferential portion  39   b  is subjected to an electrical potential. As the disc  38  rotates, different combinations of the contacts  41  come into contact with the outer circumferential portion  39   b.  The contacts  41  in contact with the disc register the voltage potential of the outer circumferential portion  39   b.  The specific combination of contacts  41  registering contact with the disc  38  when the disc  38  is located at a particular angular position is unique to that position, and can thus be used as an indication of the angular position of the spindle  42 . 
         [0036]    The rotary encoder  34  is electrically connected to an amplifier  43  of the radio  10  via the bus  44 , so that the amplifier  43  receives the output of the rotary encoder  34 . The amplifier  43  and bus  44  are depicted schematically in  FIG. 5 . The amplifier  43  is configured to recognize the various combinations of energized contacts  41  with the disc  38  of the rotary encoder  34  as indicative of the angular position of the spindle  42 . The amplifier  43  is electrically connected to the speaker  14 , and generates an electrical output that drives the speaker  14 . The amplifier  43  is configured so that its power output, and the resulting volume of the speaker  14 , vary in response to the position signal from the rotary encoder  34 . 
         [0037]    A knob  50  is securely mounted on the upper or second portion of the spindle  42 , as shown in  FIGS. 2 and 3 . The knob  50  is secured to the spindle  42  by an interference fit between the end of the spindle  42  and a sleeve  51  on the knob  50 . Other suitable retaining means, such as fasteners and/or adhesive, can be used in addition to, or in lieu of an interference fit. 
         [0038]    The user can vary the volume of the speaker  14  by rotating the knob  50 . In particular, because the knob  50  is secured to the second portion of the spindle  42 , rotation of the knob  50  imparts a corresponding rotation to the spindle  42 , which in turn results in a change in the output of the rotary encoder  34  and a corresponding change in the volume of the speaker  14 . The knob  50  can include numerical markings (not shown) denoting various volume levels. A reference mark (also not shown) can be placed on the top surface  20  of the shell  11 . The reference mark and the numerical markings on the knob  50  can provide the user with a visual indication of the volume setting for the speaker  14 . 
         [0039]    The second portion  24  of the device  12  includes a rotating platform  60 , and a microphone  26  mounted on the rotating platform  60 , as illustrated in  FIGS. 2-4 . The microphone  26  is a surface-mount microelectromechanical systems (MEMS) microphone. The microphone  26  can include, for example, a flexible, pressure-sensitive diaphragm or membrane (not shown), and a fixed back plate (also not shown) that faces, and is spaced apart from the diaphragm. The diaphragm and the back plate, when electrically charged, act as a capacitor. The diaphragm is deflected by sound pressure, which produces a corresponding change in capacitance of the diaphragm. The change in capacitance of the diaphragm results in a corresponding change in the voltage across the diaphragm and the back plate, which can be correlated to the sound pressure level. 
         [0040]    The microphone  26  has a unidirectional cardioid pick up pattern, so that the sensitivity of the microphone  26  is higher over a first, or front half thereof than over a second, or back half thereof. This feature helps to minimize the pick up of ambient sounds during operation of the microphone  26 . Microphones other than MEMS microphones, such as electret condenser microphones, can be used in lieu of the microphone  26 . Moreover, microphones having pick-up patterns other than unidirectional, such as omnidirectional and bidirectional patterns, can be used instead of the microphone  26 . A microphone suitable for use as the microphone  26  can be obtained, for example, from Analog Devices Inc. as the ADMP401 model MEMS microphone. 
         [0041]    The rotating platform  60  allows the user to adjust the angular position of the microphone  26  independently of the angular position of the knob  50 , so that the acoustically-sensitive front half of the microphone  26  can face the user when the radio  10  is in a particular orientation in relation to the user. The rotating platform  60  includes a base  68  that is securely mounted on a top surface of the knob  50  by a suitable means such as adhesive, as depicted in  FIG. 4 . The rotating platform  60  also includes a carousel  70  that is mounted for rotation on the base  68  via a bearing  73 . The microphone  26  is securely mounted on the carousel  70  using a suitable means such as adhesive. The microphone  26  can thus rotate in relation to the knob  50  and the shell  11 . Means other than the rotating platform  60  can be used in alternative embodiments to facilitate relative rotational movement between the microphone  26  and the knob  50 . 
         [0042]    A protective cover  71  for the microphone  26  is mounted on the carousel  70  of the rotating platform  60 , as shown in  FIGS. 2-4 . The cover  71  can be formed from an impact resistant material such as high-impact plastic, and can have holes formed therein to facilitate the passage of sound therethrough. The cover  71  can include reference marks (not shown) that provide the user with a visual indication of the location of the acoustically-sensitive front half of the microphone  26 . 
         [0043]    Signals can be transmitted between the microphone  26  and electrically-conductive leads (not shown) mounted on an interior surface of the knob  50  by way brushes or slip contacts  72  mounted on the base  68  of the rotating platform  60 , and slip rings  74  mounted on the carousel  70 , as depicted in  FIGS. 4 and 5 . The signals can be transmitted between the electrically-conductive leads on the knob  50 , and the shell  11  of the radio  10  via brushes or slip contacts  76  mounted on the top surface  20  of the shell  11 , and slip rings  78  mounted on the interior surface of the knob  50  as shown in  FIG. 3 . Signals can be transmitted between the knob  50  and the shell  11  using alternative means such as a simple twisting wire structure, acoustic coupling, optical coupling, and RF coupling. 
         [0044]    During use of the radio  10 , the user can rotate the knob  50  to adjust the volume of the speaker  14  to a desired level, as discussed above. The user can then rotate the carousel  70  of the rotating platform  60  to adjust the angular position of the microphone  26 , so that the front of the microphone  26  faces the user or other sound source to be picked up by the microphone  26 . Because the resistance of spindle  42  of the rotary encoder  34  to rotation is greater than that of the carousel  70 , rotation of the carousel  70  does not impart rotation to the knob  50  or the spindle  42 , and thus does not affect the volume setting of the speaker  14 . 
         [0045]    Integrating the microphone  26  into a device  12  that also performs the function of volume control can eliminate the need to dedicate a separate space on the radio  10  for the microphone  26 . Moreover, a volume knob or other protrusion located on the top surface  20  of the radio  10 , in general, is an advantageous mounting location for a microphone because such protrusions usually are not covered during normal operation of the radio  10 . Also, the ability to accommodate a microphone using space dedicated to another component can allow the use of functions requiring multiple microphones, such as noise cancellation, sound localization, and sound isolation, in applications where spatial constraints would otherwise preclude the use of multiple microphones. 
         [0046]    The microphone  26  can be integrated with components other than a volume control knob in alternative embodiments. For example, the microphone  26  can be integrated with a mode-select switch or other protruding features on the radio  10 . In other alternative embodiments, the spindle  42  of the rotary encoder  34  can be configured to rotate with the microphone  26 , and the output of the rotary encoder  34  can be used to provide an indication of the angular position of the microphone  26 . 
         [0047]    In other alternative embodiments, the microphone  26  can be mounted on a projection having the sole purpose of accommodating the microphone  26 . For example,  FIG. 16  depicts an alternative embodiment in which an acoustic transducer, such as the microphone  26 , is mounted on a projection  98  that extends from the top surface  20  of the shell  11 . In other alternative embodiments, one or more of the projection  98  can be formed at other locations on the shell  11  at which it may be critical or otherwise preferable to locate a microphone  26  for noise cancellation or other purposes. 
         [0048]    In alternative embodiments that utilize an omnidirectional microphone  26 , there is no need to rotate the microphone  26  in relation to the knob  50  or the shell  11  to orient the microphone  26  for optimal pick-up. Thus, the microphone  26  can be mounted directly on the knob  50  in such embodiments, without the use of the rotating platform  60  or other structure that facilitates relative rotational movement between the microphone  26  and the knob  50 . 
         [0049]      FIG. 6  depicts an alternative embodiment in the form of an integrated volume control and microphone device  100 . Components of the device  100  that are substantially identical to those of the device  12  are denoted in the figures by identical reference characters. The device  100  includes a first portion  102 , and a second portion  104 . The first portion  102  includes a rotary encoder  106  having a casing  108  and a spindle  110 . A first portion of the spindle  110  is disposed for rotation within the casing  108 , and a second portion of the spindle  110  extends from the casing  108 . The rotary encoder  106  generates an electrical output indicative of the angular position of the spindle  110 , in a manner substantially the same as the rotary encoder  34 . The first portion  102  of the device  100  also includes a knob  111  securely mounted on the second portion of the spindle  110 , so that rotation of the knob  111  imparts a corresponding rotation to the spindle  110 . 
         [0050]    The second portion  104  of the device  100  includes a base  116  that is securely mounted on the top surface  20  of the shell  11  by a suitable means such as fasteners or epoxy. The second portion  104  also includes a shaft  118  that adjoins the base  116 . The shaft  118  extends upwardly though the casing  108  of the rotary encoder  106 . The shaft  118  also extends through a channel  120  that is formed within the spindle  110 , along the longitudinal axis thereof. The first and second portions  102 ,  104  of the device  100  are thus disposed in a coaxial configuration. The shaft  118  also extends through a centrally-located hole  119  in the upper portion of the knob  111 . The channel  120 , the hole  119 , and the portion of the shaft  118  extending through the channel  120  are depicted in phantom in  FIG. 6 . 
         [0051]    The rotating platform  60  has an acoustic transducer, such as the microphone  26 , mounted thereon as discussed above in relation to the device  12 . The rotating platform  60  can be securely mounted on top of the shaft  112  using fasteners or other suitable means. Signals for the microphone  26  are routed between the slip contacts  72  on the base  68  of the rotating platform  60 , and the shell  11  of the radio  10  by way of electrically-conductive leads (not shown) that extend along the side of the shaft  118 . As a result of the coaxial arrangement of the shaft  118  and the spindle  110 , rotation of the knob  111  is not imparted to the rotating platform  60  or the microphone  26 , and vice versa. Thus, the volume of the speaker  14  can be adjusted without changing the angular position of the microphone  26 , and the orientation of the microphone  26  can be adjusted without changing the volume setting of the radio  10 . 
         [0052]      FIGS. 7 and 8  depict another alternative embodiment in which the radio  10  is equipped with a GPS antenna  260 . The antenna  260  has an elongated body  262  mounted on the top surface  20  of the radio  10 . The body  262  has an upper portion  264   a  and a lower portion  264   b.  The lead (not shown) for the antenna  260  is mounted within the lower portion  264   b  of the body  262 . The antenna  260  provides inputs to the GPS module  89  of the radio  10  via the bus  44 . An acoustic transducer, such as the microphone  26 , is mounted on an outer surface  266  of the upper portion  264   a,  as shown in  FIG. 8 . A protective cover  267 , similar to the cover  71  of the device  12 , is mounted on the outer surface  266  and over the microphone  26 . The cover  267  is depicted in phantom in  FIG. 8 . In alternative embodiments, the microphone  26  can be positioned within an open recess that is formed in the body  202  and extends inwardly from the outer surface  204 . In other alternative embodiments, the microphone  26  can be embedded within a cavity formed within the body  202 , and sound can be routed to the microphone  26  via an acoustical tube embedded within the body  202 , or by other suitable means. 
         [0053]      FIG. 9  depicts another alternative embodiment in the form of an antenna  280  configured to transmit and receive radio frequency (RF) signals. The antenna  260  provides inputs to, and receives outputs from the transmit and receive module  80  of the radio  10  via the bus  44 . The antenna  280  comprises a cover  282  formed from a material such as polyvinyl chloride (PVC) or polyurethane, and a lead  284  embedded in the cover  282 . The lead  284  is depicted in phantom in  FIG. 9 . The antenna  280  also includes a microphone module  286 . The microphone module  286  includes a body  288  that adjoins the cover  282 , and an acoustic transducer, such as the microphone  26 , mounted in a recess formed in an outer surface of the body  288 . A shielded feed  290  for the lead  284  extends through the body  288 . 
         [0054]    The microphone module  286  also includes a shield  292  positioned between the body  288  and the cover  282 , to help shield the microphone  26  from RF energy radiated by the lead  284 . In alternative embodiments, the microphone  26  can be mounted on the outer surface of the body  288 . In other alternative embodiments, the microphone  26  can be embedded in the body  288 . Sound can be routed to the microphone  26  via an acoustical tube or other suitable means. The acoustical tube can be embedded within the body  288 , and can extend radially outward to the outer surface of the body  288 . Alternatively, the acoustical tube can direct sound to the microphone  26  from the top of the antenna  280 . The acoustical tube in such an embodiments can be embedded in the cover  282  and the body  288 , can extend along the axial, i.e., lengthwise, direction of the antenna  280 , and can terminate at or near an upper surface the cover  282 . 
         [0055]      FIGS. 10 and 11  depict another alternative embodiment in the form of a collar  200 . The collar  200  comprises a ring-shaped body  202  having an outer surface  204  and an inner surface  206 . The collar  200  also includes an acoustic transducer such as the microphone  26 . The microphone  26  is mounted on the outer surface  204  of the collar  200 . A protective cover  207 , similar to the cover  71  of the device  12 , can be mounted on the outer surface  204  and over the microphone  26 . A suitable marking (not shown) can be placed on the outer surface  204  to indicate the position of the microphone  26  to the user. 
         [0056]    In alternative embodiments, the microphone  26  can be positioned within an open recess that is formed in the body  202  and extends inwardly from the outer surface  204 . In other alternative embodiments, the microphone  26  can be embedded within a cavity formed within the body  202 , and sound can be routed to the microphone  26  via an acoustical tube embedded within the body  202 , or other suitable means. In other alternative embodiments, the body  202  and the microphone  26  can be covered with a protective means, such as GORE-TEX fabric, to protect the collar  200  from ingress of water and other contaminants. 
         [0057]    The collar  200  is configured to fit over the GPS antenna  85  of the radio  10 , as shown in  FIG. 10 . The collar  200  can be configured to fit over other protrusions or projections formed in, or mounted on the shell  11  in alternative embodiments. The antenna  85  provides inputs to the GPS module  89  of the radio  10  via the bus  44 . The GPS module uses the input to determine the position of the radio  10 . Alternative embodiments of the collar  200  can be configured to be placed over protruding structures other than the GPS antenna  85 . The collar  200  can be retained on the antenna  85  by a suitable means such as an interference, or friction fit. In particular, the diameter of the inner surface  206  of the collar  200  can be selected so that friction between the inner surface  206  and the contacting surface of the antenna  85  is sufficient to prevent the collar  200  from slipping off the antenna  85 , but low enough to permit the user to rotate the collar  200  in relation the antenna  85  to place the microphone  26  in an optimum orientation in relation to the sound source being picked up by the microphone  26 . Alternatively, a clip or ring (not shown) can be secured to the antenna  85  above the collar  200  after the collar  200  has been placed on the antenna  85 , to prevent the collar  200  from disengaging from the antenna  85 . 
         [0058]    A cable  216  is mechanically connected to the collar  200 , as shown in  FIGS. 10 and 11 . The cable  216  is electrically connected to the microphone  26 . A connector, such as a universal serial bus (USB) standard Type A plug connector  218 , is connected to the freestanding end of the cable  216  as illustrated in  FIG. 10 . The connector  218  can be mated with a suitable receptacle connector, such as a USB standard Type A receptacle connector  220 , mounted on the radio  10  to communicatively couple the microphone  26  to the radio  10 . The collar  200  can thus be retro-fitted to an existing radio, such as the radio  10 , or other communication devices with relative ease. 
         [0059]    Alternative embodiments of the collar  200  can include multiple microphones  26 , for purposes such as beam forming in which sound is to be picked up from a particular direction. Also, in applications where it is not feasible to rotate the collar  200  in relation the antenna  85 , multiple microphones  26  can be used to help ensure that a microphone  26  is generally oriented toward the sound to be picked up regardless of the angular position of the antenna  85  in relation to the sound source. 
         [0060]      FIGS. 12 and 13  depict another alternative embodiment in the form of a first collar  230  and a second collar  232 . The first and second collars  230 ,  232  are configured to be positioned around the RF antenna  87  of the radio  10 . The antenna  87  provides inputs to, and receives outputs from the transmit/receive module  80  of the radio  10  via the bus  44 . The transmit/receive module  80  demodulates and performs other signal processing operations on the inputs it receives from the RF antenna  87 . The transmit/receive module  80  also performs modulation and other signal processing operations to generate RF outputs that are transmitted by the antenna  87 . 
         [0061]    The first collar  230  is substantially similar to the collar  200  described above, with the following exceptions. The first collar  230  is sized to fit over the RF antenna  87  instead of the GPS antenna  85 . Also, the first collar  230  includes noise-cancellation circuitry  240  as depicted in  FIG. 13 . The noise-cancellation circuitry  240  is communicatively coupled to acoustic transducer, i.e., the microphone  26 , of the first collar  230  via wiring internal to the first collar  230 . The first collar  230  further includes a cable  238 , in addition to the cable  216 . The cable  238  electrically interconnects the first collar  230  to the second collar  232 . Alternative embodiments of the collars  230 ,  232  can each include multiple microphones  26 , as discussed above in relation to the collar  200 . 
         [0062]    The second collar  232  is substantially similar to the collar  200  described above, with the exception that the second collar  232  does not include a cable  216 , or noise-cancellation circuitry  240 . The microphone  26  of the second collar  232  is communicatively coupled to the noise-cancellation circuitry  240  of the first collar  230  via the cable  216 . Alternative embodiments of the collars  230 ,  232  can each include multiple microphones  26 , as discussed above in relation to the collar  200 . 
         [0063]    The noise-cancellation circuitry  240  can be configured to perform the noise-cancellation function by any suitable technique. For example, the microphone  26  of the first collar  230  can be treated as a primary microphone, i.e., the microphone positioned closest to the user&#39;s mouth or other audio source that the user wishes to be picked-up. The output the secondary microphone  26  of the second collar  232  will generally reflect a higher percentage of background noise, and a lower percentage of the audio source that the user wishes to be picked-up in comparison to the primary microphone  26  of the first collar  230 . Thus, by generating an output that represents the difference between the outputs of the primary and secondary microphones, the noise-cancellation circuitry  240  can eliminate some of the background noise incident upon the primary microphone  26 . Additional information relating to noise-cancellation techniques can be found in pending U.S. patent application Ser. No. 12/403,646, filed Mar. 13, 2009, the contents of which is incorporated by reference herein in its entirety. 
         [0064]    The user can adjust the relative positions of the first and second collars  230 ,  232  by moving the first and second collars  230 ,  232  up or down the antenna  87 . For example, the user can adjust the relative positions of the first and second collars  230 ,  232  to maximize the physical separation between the secondary microphone  26  in the first collar  230  and the primary microphone  26  in the second collar  232 , to increase the effectiveness of the noise-cancellation circuitry  240 . 
         [0065]    The first and second collars  230 ,  232  are equipped with provisions to shield the microphones  26  and other circuitry therein from the RF energy radiated by the antenna  87  when the radio  10  is transmitting. For example, a suitable shield (not shown) can be positioned around the inner circumference of the body of each of the first and second collars  230 ,  232 . Alternatively, the shielding can be integrated into each of the bodies, or the bodies themselves can be formed from a material, such as copper or silver-plated copper, that provides a shielding effect. 
         [0066]      FIG. 14  depicts an alternative embodiment of the system shown in  FIGS. 12 and 13 . In the embodiment of  FIG. 14 , a collar  250  is used in lieu of the first collar  230  of the embodiment of  FIG. 12 . The collar  250  includes a strap  252 . The collar  250  also includes an acoustic transducer, such as the microphone  26 , and noise-cancellation circuitry  240  mounted on the strap  252 , within a protective enclosure  254 . The enclosure  254  is depicted in phantom in  FIG. 14 . The microphone  26  of the collar  250  can be used as a primary microphone for the purpose of noise cancellation, and the microphone  26  of the second collar  232  can be used as a secondary microphone as discussed above in relation to the first and second collars  230 ,  232 . In other alternative embodiments, a second collar  250  can be used in lieu of the second collar  232 . 
         [0067]    The strap  252  is configured to be positioned around the shell  11  of the radio  10  as depicted in  FIG. 14 . The strap  252  can include a slider  253  or other suitable means for adjusting the length of the strap  252  to optimally fit the shell  11 . The collar  250  can also include a cable  256  that electrically connects the noise-cancellation circuitry  240  to the microphone  26  of the second collar  232 . The collar  250  also includes a cable and connector (not shown), such as the cable  216  and connector  218  of the collars  200 ,  230 , to electrically connect the collar  250  to the radio  10 . Because the collar  250  can be placed around the shell  11  of the radio  10 , the spacing between the microphones  26  of the collar  250  and the second collar  232  can be greater than that between the microphones  26  of the first and second collars  230 ,  232  mounted on the antenna  87 . Increasing the spacing between the microphones  26  of the collar  250  and the second collar  232  in this manner can potentially increase the effectiveness of the noise cancellation provided by the noise-cancellation circuitry  240 . 
         [0068]      FIG. 15  depicts another alternative embodiment in the form of an adapter  300  configured to mate with the input/output jack  90  of the radio  10 . The input/output jack  90  is configured to mate with, for example, an accessory connector (not shown). The input/output jack  90  is covered by the adapter in  FIG. 15 ; the input/output jack  90  is visible in the embodiment depicted in  FIG. 1 . The adapter  300  includes a body  302 . A lower portion  304  of the body  302  is configured with pins (not shown) that each mate a corresponding receptacle of the input/output jack  90 . 
         [0069]    The body  302  includes an intermediate portion  308 . An acoustic transducer, such as the microphone  26 , can be mounted on an outer surface  310  of the intermediate portion  308 . A protective cover (not shown) similar to the cover  71  of the device  12  is mounted on the outer surface  310 , over the microphone  26 . In alternative embodiments, the microphone  26  can be positioned within an open recess that is formed in the intermediate portion  308  and extends inwardly from the outer surface  310 . In other alternative embodiments, the microphone  26  can be embedded within a cavity formed within the intermediate portion  308 , and sound can be routed to the microphone  26  via an acoustical tube embedded within the intermediate portion  308 , or by other suitable means. Signals from the microphone  26  can be routed to the radio  10  via one of the pins of the lower portion  304 . 
         [0070]    The body  302  further includes an upper portion  312 . The upper portion  312  includes a receptacle  314  configured to mate with the accessory connector.