Patent Publication Number: US-9838769-B2

Title: Microphone shield

Description:
This application claims priority under 35 U.S.C. §119 to U.S. patent application Ser. No. 62/214,058, which was filed on Sep. 3, 2015 and is expressly incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to an apparatus to minimize noise at a microphone, more particularly, to a microphone shield positioned near a microphone during use. 
     BACKGROUND 
     The dual purpose of a microphone shield is to block reverberant energy from the room boundaries behind and to the sides of the microphone, while absorbing any sound that enters the device from the rear. 
     The current state of the art for portable, rigid, stand mounted microphone shields uniformly consists of curved, concave (when viewed from the inside of the device) and/or flat faceted designs that encircle the microphone on three sides. They are all lined with acoustically absorbent material, typically open cell polyurethane foam, or in some cases a layer of nonwoven fibers. The purpose of this absorptive lining is to reduce the level of any internal reflections that may occur from the shell of the shielding device itself caused by direct sound entering the open portion of the shell. This energy can be reflected directly back at the microphone causing unwanted sonic colorations. 
     There are two design approaches to the structural shell that surrounds the microphone and supports the absorptive material, perforated and solid. The shells that are perforated do a poor job of isolating the microphone from ambient room reflections but to a large degree do not have any, or as much, internal reflections. Solid shells do a much better job of isolating the microphone from the acoustical influence of the room but their mostly semi-circular or concave shape (when viewed from the inside) tend to reflect some level of acoustical energy back to the microphone. 
     SUMMARY 
     According to one aspect, a microphone shield is disclosed. The microphone shield includes a number of panels configured to be positioned around a point in space at which a microphone may be positioned. The shield may also include a number of acoustic liners that are coupled to the panels. Each liner has a geometric profile on the surface facing the point at which the microphone may be positioned. At least one of these sound-facing surfaces is configured to define an arc that is convex in shape relative to the point in space. In some embodiments, at least one of the panels of the shield may be configured to define an arc that is convex in shape relative to the point in space. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The detailed description particularly refers to the following figures, in which: 
         FIG. 1  is a simplified diagram of radiating energy reflecting from a smooth, flat surface; 
         FIG. 2  is a simplified diagram of radiating energy reflecting from a diffusing convex surface; 
         FIG. 3  is a top plan view of an embodiment of a microphone shield, this embodiment defining a single convex arc facing a central point; 
         FIG. 4  is a top plan view of another embodiment of a microphone shield; 
         FIG. 5  is a top plan view of another embodiment of a microphone shield, this embodiment defining multiple convex arcs facing a central point; 
         FIG. 6  illustrates a perspective view of another embodiment of the microphone shield; 
         FIG. 7  illustrates a top plan view of the microphone shield of  FIG. 6 ; 
         FIG. 8  illustrates a bottom plan view opposite the top plan view of  FIG. 7 ; 
         FIG. 9  illustrates a front elevation view of the microphone shield of  FIG. 6 ; 
         FIG. 10  illustrates a rear elevation view of the microphone shield of  FIG. 6 ; 
         FIG. 11  illustrates a side elevation view of the microphone shield of  FIG. 6 , with the opposite side elevation view being the mirror image of  FIG. 11 ; 
         FIGS. 12-14  are simplified graphs showing the frequency responses of sound energy reflected from various microphone shield shells and detected by an omni-directional microphone; 
         FIG. 15  is a simplified graph showing the frequency responses of sound energy reflected from various microphone shield shells and detected by a cardioid microphone; 
         FIGS. 16-18  are simplified graphs showing the frequency responses of sound energy reflected from various microphone shield shells with acoustic liners and detected by an omni-directional microphone; 
         FIGS. 19-21  are simplified graphs showing the frequency responses of sound energy reflected from various microphone shield shells with acoustic liners and detected by a cardioid microphone; 
         FIG. 22  is a simplified graph showing the frequency responses of sound energy reflected from various microphone shield shells and detected by a omni-directional microphone; 
         FIG. 23  is a simplified diagrammatic top plan view of a testing room used to test the sound absorptive properties and the sound reflective properties of one or more microphone shields; 
         FIG. 24  is a perspective view of an unlined microphone shield shell with an omni-directional microphone positioned at a central point; 
         FIG. 25  is a perspective view of a microphone shield including an acoustic liner, with an omni-directional microphone positioned at a central point; 
         FIG. 26  is a perspective view of a microphone shield including an acoustic liner, with a cardioid microphone positioned at a central point; and 
         FIG. 27  illustrates an exploded perspective view of another embodiment of a microphone shield; 
         FIGS. 27A-C  illustrate a number of attachment mechanisms for the microphone shield of  FIG. 27 ; and 
         FIG. 28  illustrates a perspective view of the disassembled components of the microphone shield of  FIG. 12A . 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     While the concepts of the present disclosure are susceptible to various modifications and alternative forms, specific exemplary embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit the concepts of the present disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. 
     Referring now to  FIG. 1 , sound waves  2  generated by a sound source  4  radiate outward from the source  4 . When the waves  2  encounter a substantially smooth wall or surface  6  with no diffusing material, the waves  2  are reflected. As shown in  FIG. 1 , the reflected waves  2  remain relatively concentrated. If the waves  2  are reflected back toward a microphone, the concentration of the waves adds some amount of undesired spectral coloration to the recorded audio signal. 
     A microphone shell, by necessity needs to wrap around the rear and sides of the microphone as much as possible to shield the microphone from back and sidewall room reflections. The resulting curved or arced shape of shell can cause energy or waves that do make it into the shell to be focused toward the microphone. Most of this is mitigated by the absorptive lining inside of the shell but not all of this energy is absorbed. This adds some amount of undesired spectral coloration to the recorded audio signal. As shown in  FIG. 2 , a convex profile  8  of the inside surfaces of the panels distributes this unabsorbed or reflected waves over a wider angle instead of focusing or concentrating it at the microphone location. 
     Referring to  FIG. 3 , a microphone shield  10  comprising a shell  12  and acoustic liner  14  is shown. The illustrative microphone shield  10  curves around a point  16 . In use, a microphone (not shown) is positioned at or near the point  16 , and the microphone shield is configured to block/absorb unwanted reflected sound energy before it reaches the microphone. The illustrative shell  12  includes a central panel  18 , a first outer panel  20 , and a second outer panel  22 . In some embodiments, the shell  12  includes more or less supports than those shown in  FIG. 3 . Each of the panels  18 ,  20 ,  22  include a first surface  24  facing away from the point  16  and a second surface  26  facing towards the point  16 . In the illustrative embodiment shown in  FIG. 3 , the central panel  18  is arced such that the second surface  26  of the central panel  18  is a convex surface facing the point  16 . Such a convex second surface  26  of the central support is configured to act as a diffuser of sound energy. 
     Acoustic liners  28 ,  30 ,  32  are coupled to the second surface  26  of each panel  18 ,  20 ,  22 . In the illustrative embodiment, the acoustic liners  28 ,  30 ,  32  are made of an acoustically absorbent material, such as, for example, open cell polyurethane foam, or a layer of nonwoven polyester fibers. The acoustic liners  28 ,  30 ,  32  include a geometric profile  34 . In the illustrative embodiment, the geometric profile  34  is that of a series of triangles extending the height of the acoustic liners  28 ,  30 ,  32 . In other embodiments, the acoustic liners may include number of different geometric profiles, such as, for example, a series of triangles extending across the width of an acoustic liner, a series of semi-circles extending the height of an acoustic liner, a series of squares extending the height of an acoustic liner, a series of pyramids repeating across the area of an acoustic liner, a series of squares repeating in a checkered pattern across the area of an acoustic liner, where a first square extends a first height away from a support and a second square extends a second height away from the support, such that the first height is different than the second height. 
     Each acoustic liner  28 ,  30 ,  32  extends from a panel-facing surface  36  configured to couple to the second surface  26  of a panel  18 ,  20 ,  22 , and terminates in one or more sound-facing surfaces  38 . In the illustrative embodiment, the one or more sound-facing surfaces  38  are one or more tips of the triangle of the geometric profile  34 . Additionally, the one or more sound-facing surfaces  38  of each acoustic liner  28 ,  30 ,  32  are configured to define an arc. In the illustrative embodiment, the sound-facing surfaces  38  of the central acoustic liner  28  form a central arc  40  that is convex in shape, relative to the point  16 ; the sound-facing surfaces  38  of the first acoustic liner  30  form a first arc  42  that is straight in shape; and the sound-facing surfaces  38  of the second acoustic liner  32  form a second arc  44  that is straight in shape. 
     Referring to  FIG. 4 , an embodiment of the microphone shield  110  having a shell  112  and acoustic liners  114 , curved around a point  116  (i.e., the microphone location) is shown. The microphone shield  110  is similarly embodied as the microphone shield  10  of  FIG. 3 . As such, parts with similar numbering serve similar functions, and full descriptions of those parts are not repeated here. 
     As shown in  FIG. 4 , a central panel  118  of the microphone shield is arced such that a second surface  126  of the central panel  118  forms convex shape, relative to a point  116 . Each of a first panel  120  and a second panel  122  are arced such that their respective second surfaces  126  form a concave shape, relative to the point  116 . 
     Additionally, each of the sound-facing surfaces  138  of the acoustic liners  128 ,  130 ,  132  are configured to define an arc. A central arc  140  formed by the microphone shield  110  is a convex shape, relative to the point  116 . A first arc  142  and a second arc  144  formed by the microphone shield  110  is concave in shape, relative to the point  116 . 
     Referring to  FIG. 5 , an embodiment of the microphone shield  210  having a shell  212  and acoustic liners  214 , curved around a point  216  is shown. The microphone shield  210  is similarly embodied as the microphone shield  10  of  FIG. 3 . As such, parts with similar numbering serve similar functions, and full descriptions of those parts are not repeated here. 
     As shown in  FIG. 5 , a central panel  218  of the microphone shield is arced such that a second surface  226  of the central panel  218  forms convex shape, relative to a point  216  (i.e., the microphone location). Each of a first panel  220  and a second panel  222  are arced such that their respective second surfaces  226  also form a convex shape, relative to the point  216 . 
     Additionally, each of the sound-facing surfaces  238  of the acoustic liners  228 ,  230 ,  232  are configured to define an arc. A central arc  240  formed by the microphone shield  210  is a convex shape, relative to the point  216 . A first arc  242  and a second arc  244  formed by the microphone shield  210  is convex in shape, relative to the point  216 . Arcs  240 ,  242 ,  244  are configured to diffuse sound energy reflected by the panels of the shell  212  and not fully absorbed by the acoustic liners  228 ,  230 ,  232 . 
     Referring now to  FIGS. 6-11 , another embodiment of the microphone shield  250  is shown. The microphone shield  250  includes features similar to those described above in regard to the shield  210 . Accordingly, the reference numbers used above in regard to the shield  210  will be used to describe the same or similar features of the shield  250 . As shown in  FIG. 6 , the microphone shield  250  has a shell  212  and a number of acoustic liners  252  that are positioned around a point  216 . The microphone shield  250  also includes a mounting bracket  254  secured to the bottom of the shell  212 . The bracket  254  is configured to be secured to a stand or support positioned near a microphone (not shown) located at the point  216 . 
     In the illustrative embodiment, the shell  212  is formed as a single monolithic component from a rigid plastic material. It should be appreciated that in other embodiments the shell may be formed as separate pieces that are later assembled and may be formed from other materials including, for example, hardwoods. Each acoustic liner  252  is made of an acoustically absorbent material, such as, for example, open cell polyurethane foam, or a layer of nonwoven polyester fibers. As described in greater detail below, each of the liners  252  of the microphone shield  250  has a different geometric profile  34 . 
     Referring now to  FIG. 7 , the shell  212  includes a central panel  256  and a pair of side panels  258 ,  260  positioned on either side of the panel  256 . The central panel  256  has an inner surface  262  that faces toward the point  216 . In the illustrative embodiment, the inner surface  262  is a convex curved surface that is bowed toward the point  216 . The surface  262  includes a central section  264  that is positioned between a pair of side sections  266 . The sections  266  cooperate to define a curved arc  268  that has a convex shape relative to the point  216 . The central section  264  defines another curved arc  270  that also has a convex shape relative to the point  216 . As shown in  FIG. 7 , the curved arc  268  has a radius of curvature R 1 , and the curved arc  270  has a radius of curvature R 2  that is less than the radius R 1 . In the illustrative embodiment, R 2  is equal to about 1.0 inches, and R 1  is equal to about 6.0 inches. It should be appreciated that in other embodiments the dimensions of R 1 , R 2  may be different depending on, for example, the size and type of microphone. 
     The side panel  258  of the shell  212  is connected to one end of the central panel  256 . In the illustrative embodiment, the side panel  260  of the shell  212  is connected to the opposite end of the central panel  256  and has a configuration that is the mirror image of the side panel  258 . Each of the side panels  258 ,  260  has an inner surface  272  that faces toward the point  216 , and the inner surface  272  of each of the panels  258 ,  260  is a convex surface that is bowed toward the point  216 . As shown in  FIG. 7 , each inner surface  272  defines a curved arc  274  that also has a convex shape relative to the point  216 . The curved arc  274  has a radius of curvature R 3  in the illustrative embodiment. In the illustrative embodiment, R 3  is equal to about 12 inches. It should be appreciated that in other embodiments the dimension of R 3  may be different depending on, for example, the size and type of microphone. 
     In the illustrative embodiment, an acoustic liner  214  is attached to each of the panels  256 ,  258 ,  260 . The liners  214  include a central liner  276  attached to the panel  256  and a pair of side liners  278 ,  280  attached to the side panels  258 ,  260 , respectively. 
     The central liner  276  has an inner surface  282  that faces toward the point  216 . In the illustrative embodiment, the inner surface  282  is a convex curved surface that is bowed toward the point  216 . The surface  282  includes a central section  284  that is positioned between a pair of side sections  286 . The sections  284 ,  286  cooperate to define the geometric profile  34  of the liner  276 . The sections  286  define a curved arc  288  that has a convex shape relative to the point  216 . The central section  284  defines another curved arc  290  that also has a convex shape relative to the point  216 . In the illustrative embodiment, the curved arc  288  has the radius of curvature R 1  (the same as the curved arc  268  defined by the surface sections  266  of the panel  256 ), and the curved arc  290  has the radius of curvature R 2  (the same as the curved arc  270  defined by the surface  264  of the panel  256 ). 
     The side liner  278  of the shield  250  is positioned at one end of the central liner  276  on the panel  258 . In the illustrative embodiment, the other side liner  280  is positioned at the opposite end of the central liner  276  on the panel  260  and has a configuration that is the mirror image of the side liner  278 . Each of the side liners  278 ,  280  has an inner surface  292  that faces toward the point  216 , and the inner surface  292  of each of the liners  278 ,  280  is bowed toward the point  216 . As shown in  FIG. 7 , each inner surface  292  defines a curved arc  294  that also has a convex shape relative to the point  216 . 
     In the illustrative embodiment, the geometric profile  34  of the liners  278 ,  280  is defined by a number of triangles  296 . Each triangle  296  extends from a base  298  attached to a liner body  300  to a tip  302 . The tips  302  cooperate to define the curved arc  294 , as shown in  FIG. 7 . The curved arc  294  has the radius of curvature R 3  in the illustrative embodiment. 
     In other embodiments, the acoustic liners may include number of different geometric profiles, such as, for example, a series of triangles extending across the width of an acoustic liner, a series of semi-circles extending the height of an acoustic liner, a series of squares extending the height of an acoustic liner, a series of pyramids repeating across the area of an acoustic liner, a series of squares repeating in a checkered pattern across the area of an acoustic liner, where a first square extends a first height away from a support and a second square extends a second height away from the support, such that the first height is different than the second height. 
     In the illustrative embodiment of  FIGS. 6-11 , the mounting bracket  254  extends outwardly from the shell  212 . When attached to a stand or support, the bracket  254  is configured to extend generally parallel to the ground. As shown in  FIGS. 6-9 , the inner surfaces  272 ,  282  of the liners  252  extend in a generally perpendicular or orthogonal direction relative to the mounting bracket  254 . It should be appreciated that in other embodiments the surfaces  272 ,  282  may be, for example, curved or angled relative to the mounting bracket  254  (and/or the ground). 
     Referring to  FIGS. 12-14 , three graphs  304 ,  306 ,  308  of frequency responses of reflected sound energy received by an omni-directional microphone are shown. An exemplary test room  798  is shown in diagrammatic form in  FIG. 23 , with the microphone  800  positioned adjacent the microphone shield under test. An exemplary omni-directional microphone  800  with the microphone shield  210  is shown in  FIG. 23 . Returning to  FIGS. 12-14 , the line  310  represents the frequency response of reflected sound energy received by an omni-directional microphone when a prior art microphone shield, the Mudguard™, which is commercially available from Auralex Acoustics, is used to protect the microphone with the liner removed. The line  312  represents the frequency response of reflected sound energy received by the omni-directional microphone when the microphone shield  210  having panels with convex-shaped surfaces  226  and no acoustic liner is used to protect the microphone from sound energy reflections. The line  314  represents the frequency response of reflected sound energy received by the omni-directional microphone when no microphone shield is used to protect the microphone. All measurements are of sound energy reflected back to the microphone by the microphone shell. The lower the number, the less sound energy that is received by the microphone. As shown in  FIGS. 12-14 , the shield  210 , even without an acoustic liner, tested better in low frequencies (below 400 Hz) where sound wavelength is harder to control and in mid-band frequencies (800-1500 Hz) where the human ear is the most sensitive. 
     Referring now to  FIG. 15 , a graph  400  of frequency responses of reflected sound energy received by a cardioid microphone  802  is shown. The line  410  represents the frequency response of reflected sound energy received by a cardioid microphone when a prior art microphone shield having no acoustic liner is used to protect the microphone from reflected sound energy. The line  412  represents the frequency response of reflected sound energy received by the cardioid microphone when the microphone shield  210  having panels with convex shaped second surfaces  226  and no acoustic liner is used to absorb internal reflections that might strike the microphone. The line  414  represents the frequency response of reflected sound energy received by the cardioid microphone when no microphone shield is used to protect the microphone. As shown in  FIG. 15 , the shield  210 , even without an acoustic liner, tested better in low frequencies (below 500 Hz) where sound wavelength is harder to control and in mid-band frequencies (800-1750 Hz) where the human ear is the most sensitive. 
     Referring now to  FIGS. 16-18 , three graphs  500 ,  502 ,  504  of frequency responses of reflected sound energy received by the microphone  800  are shown. The line  510  represents the frequency response of reflected sound energy received by the omni-directional microphone  800  when a prior art microphone shield, the Mudguard™, which is commercially available from Auralex Acoustics, including an acoustic liner is used to protect the microphone. The line  512  represents the frequency response of reflected sound energy received by the omni-directional microphone when the microphone shield  210  forming the convex arcs  240 ,  242 ,  244  is used, as shown in  FIG. 25 , to protect the microphone  800 . The line  514  in  FIGS. 16-18  represents the frequency response of reflected sound energy received by the omni-directional microphone when no microphone shield is used to protect the microphone. As shown in  FIGS. 16-18 , the shield  210  tested better in low frequencies (below 400 Hz) where sound wavelength is harder to control and in mid-band frequencies (800-1500 Hz) where the human ear is the most sensitive. 
     Referring to  FIGS. 19-21 , three graphs  600 ,  602 ,  604  of frequency responses of reflected sound energy received by a cardioid microphone are shown. An exemplary microphone  802  positioned in the test arrangement of  FIG. 23  is shown in  FIG. 26 . The line  610  in  FIGS. 19-21  represents the frequency response of reflected sound energy received by the cardioid microphone  802  when a prior art microphone shield, the Mudguard™, which is commercially available from Auralex Acoustics, with an acoustic liner is used to protect the microphone. The line  612  represents the frequency response of reflected sound energy received by the cardioid microphone  802  when the microphone shield  210  forming the convex arcs  240 ,  242 ,  244  is used to protect the microphone, as shown in  FIG. 26 . The line  614  represents the frequency response of reflected sound energy received by the cardioid microphone when no microphone shield is used to protect the microphone. As shown in  FIGS. 19-21 , the shield  210  tested better in low frequencies (below 400 Hz) where sound wavelength is harder to control and in mid-band frequencies (700-2000 Hz) where the human ear is the most sensitive. It should be appreciated that the performance of other embodiments of the microphone shield described herein having at least one convex surface would have performance similar to the performance of the microphone shield  210  in the testing described above in reference to  FIGS. 14-21 . 
     Referring now to  FIG. 22 , a graph  700  of frequency responses of reflected sound energy received by an omni-directional microphone  800  in an anechoic environment is shown. The line  710  represents the frequency response of reflected sound energy received by the omni-directional microphone  800  when a prior art microphone shield, the Mudguard™, which is commercially available from Auralex Acoustics, including an acoustic liner is used to protect the microphone. The line  712  represents the frequency response of reflected sound energy received by the omni-directional microphone when the microphone shield  250  is used to protect the microphone. The line  714  represents the frequency response of reflected sound energy received by the omni-directional microphone when no microphone shield is used to protect the microphone. As shown in  FIG. 22 , the shield  210  reflects less sound energy to the microphone  800  than the prior art design by deviating from the line  714  less than the line  710 . It should be appreciated that the performance of other embodiments of the microphone shield described herein having at least one convex surface would have performance similar to the performance of the microphone shield  250  in an anechoic environment. 
     Referring now to  FIGS. 27-28 , another embodiment of a microphone shield  910  is shown. The microphone shield  910  includes features similar to those described above in regard to the shield  210 . Accordingly, the reference numbers used above in regard to the shield  210  will be used to describe the same or similar features of the shield  910 . As shown in  FIG. 27 , the microphone shield  910  has a shell  912  and a number of acoustic liners  214  that are positioned around a point  216 . In the illustrative embodiment, the shell  912  is an assembly including multiple components, which may be disassembled as shown in  FIG. 28  for transport. 
     As shown in  FIG. 27 , the shell  912  includes a central panel  918  that is configured to be secured to pair of side panels  920 ,  922 . Each of the panels  918 ,  920 ,  922  are arced such that their second or inner surfaces  226  form a convex shape, relative to a point  216  (i.e., the microphone location). As shown in  FIGS. 27A-C , various fastening mechanism  930 ,  932 ,  934  may be used to secure the panels  920 ,  922  to the panel  918  to form the shell  912 . The fastening mechanism  930  of  FIG. 27A  includes an extruded flange  940  formed on one of the panels  920 ,  922  that is received in a groove  942  formed on the panel  918 . The fastening mechanism  932  of  FIG. 27B  also includes an extruded flange  950  formed on one of the panels  920 ,  922  that is received in a groove  952  formed on the panel  918 . As shown in  FIG. 27B , the flange  950  includes another groove  954  sized to receive a plug (not shown) to create a “stop” and finished detail. The fastening mechanism  934  of  FIG. 27C  includes an extruded flange  960  formed on one of the panels  920 ,  922  that is received in a groove  962  formed on the panel  918 . In the embodiment of  FIG. 27C , the panel  918  may be rotated relative to the panels  920 ,  922  to disassemble the shield  910 . 
     This new device shape, consisting of one or more panels with a convex shape (when viewed from the inside of the device) that shield the microphone on three sides (behind and to each side) to reduce the amount of internal reflections seen by the microphone. The convex shape of the panels will scatter or splay the reflected energy over a wider angle making the apparent size of the reflected surface smaller from the perspective of the microphone. The typical flat to concave shapes of all other devices will tend to focus or concentrate the internal reflected energy at the microphone increasing the amount of undesirable acoustical reflections at the microphones position. 
     Some features of a microphone shield may include making a shell of the microphone shield thicker to better block sound transmission and to control any structural resonances resulting from louder sound pressure levels. The shell may be made out of decorative thermoforming sheet materials, such as wood grain. Other features of the shell may include the shell having a carbon fiber look. In yet other embodiments, the shell is made from two-ply thermoformed sheet ABS and has a soft-feel plastic veneer. Rubber feet may be included to cover the integrated feet that my protrude from the edges of the bottom of the microphone shield panels to raise the microphone shield off of a supporting surface, when not stand is used, so as to accommodate cabling from the associated microphone and reduce the change of marring the finish of the supporting surface. In some embodiments, the microphone shield includes a holder to receive a computing device, such as a smartphone or tablet. In some embodiments, the holder is formed in the acoustic liner of the microphone shield. 
     In some embodiments, the microphone shield may include an extruded metal aluminum shell with a unique perforation pattern and hollow cavities to accept a supporting tubular microphone stand or to be filled with elastomeric polymers or foam material for resonance control. The shell may also include a stamped form with embossed or recessed areas, or attachable wood panels. The shell may also be made from a thermoformed shell sheet such as a single sheet made of a single material or a single sheet made of two materials (e.g., ABS and soft feel skin may have metal trim). The shell may also include decorative thermoforming single sheet materials (e.g., Kydex). The microphone shield may also be configured to have a carbon fiber look or a soft feel. The microphone shield may also include one or more hinges configured to provide angle adjustment between the panels of the microphone shield. In some embodiments, the microphone shield includes adjustable-height rubber feet. 
     While the disclosure has been illustrated and described in detail in the drawings and foregoing description, such an illustration and description is to be considered as exemplary and not restrictive in character, it being understood that only illustrative embodiments have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected. Illustrative examples of the technologies disclosed herein are provided below. An embodiment of the technologies may include any one or more, and any combination of, the examples described below. 
     According to one example, a microphone shield comprises one or more panels positioned around a central point, and one or more acoustic liners coupled to each panel. Each of the one or more panels has a first surface facing away from the central point and a second surface facing toward the central point. The one or more acoustic liners is coupled to the second surface of each panel. Each of the one or more acoustic liners defines a geometric profile such that each acoustic liner extends from the second surface and terminates in one or more sound-absorbing surfaces. The sound-absorbing surface of at least one acoustic liner defines a curved arc that has a convex shape relative to the central point. 
     In some embodiments, the acoustic liners may comprise a central acoustic liner having the sound-absorbing surface that is bowed toward the central point to define the curved arc that is convex in shape relative to the central point, a first side acoustic liner positioned at a first end of the central acoustic liner, and a second side acoustic liner positioned at a second end of the central acoustic liner opposite the first end. The first side acoustic liner may have a sound-absorbing surface that defines a first curved arc, and the second side acoustic liner may have a sound-absorbing surface that defines a second curved arc. 
     In some embodiments, the sound-facing surfaces of the first side acoustic liner and the second side acoustic liner may have geometric profiles that are defined by a plurality of triangles, the tips of the triangles of the first side acoustic liner may define the first curved arc, and the tips of the triangles of the second side acoustic liner may define the second curved arc. 
     Additionally, in some embodiments, the sound-absorbing surface of the central acoustic liner may include a first curved section and a second curved section, and each of the first curved section and the second curved section may be defined by a first radius of curvature. A central curved section may connect the first curved section and the second curved section, and the central curved section may be defined by a second radius of curvature that is less than the first radius of curvature. 
     In some embodiments, the first curved arc and the second curved arc may be concave in shape relative to the central point. In some embodiments, the first curved arc and the second curved arc may be convex in shape relative to the central point. 
     In some embodiments, the sound-absorbing surface of the central acoustic liner may have a geometric profile that is defined by a plurality of triangles, and the tips of the triangle of the central acoustic liner may define the curved arc. In some embodiments, the one or more panels may include an arcuate panel and the second surface of the arcuate panel is bowed toward the central point. 
     Additionally, in some embodiments, the one or more panels may include a side panel extending from an end of the arcuate panel. The second surface of the side panel may extend along a substantially straight line. In some embodiments, the side panel may be a first side panel, and the one or more panels may include a second side panel extending from a second end of the arcuate panel. The second surface of the second side panel may extend along a substantially straight line. 
     In some embodiments, the acoustic liners may include a first side acoustic liner having a sound-absorbing surface that defines a substantially straight line extending parallel to the second surface of the first side panel, and a second side acoustic liner having a sound-absorbing surface that defines a substantially straight line extending parallel to the second surface of the second side panel. 
     Additionally, in some embodiments, the acoustic liners may further include a central acoustic liner coupled to the arcuate panel. The central acoustic liner may be positioned between the first and second side acoustic liners. The acoustic liner may have a sound-absorbing surface that is bowed toward the central point to define the curved arc that is convex in shape relative to the central point. 
     In some embodiments, the arcuate panel may be a central panel. The panels may include a first side arcuate panel positioned at a first end of the central panel and a second side arcuate panel positioned at a second end of the central panel opposite the first end. The second surfaces of the first side arcuate panel and the second side arcuate panel may be bowed toward the central point. 
     In some embodiments, the one or more panels may include a plurality of panels, and each panel may be removably coupled to at least one other panel. 
     According to another example, a microphone shield comprises one or more panels configured to curve around a central point and one or more acoustic liners coupled to the one or more panels. Each of the one or more panels has a first surface facing away from the central point a second surface facing toward the central point. The one or more acoustic liners are coupled to the second surface of each panel. Each of the one or more acoustic liners defines a geometric profile such that each acoustic liner extends from the second surface and terminates in one or more surfaces. The one or more surfaces of each acoustic liner is configured to define an arc that is convex in shape relative to the central point. 
     In some embodiments, the acoustic liners may comprise a central acoustic liner, a first side acoustic liner positioned at a first end of the central acoustic liner, and a second side acoustic liner positioned at a second end of the central acoustic liner opposite the first end. The first side acoustic liner may have a plurality of triangles and the tips of the triangles define one of the arcs that is convex in shape relative to the central point. The second side acoustic liner may have a plurality of triangles and the tips of the triangles define another of the arcs that is convex in shape relative to the central point. 
     According to another example, a microphone shield comprises a panel having a first surface facing away from a point and a second surface facing toward the point, and the second surface is configured to define a convex arc relative to the point. In some embodiments, the shield may further comprise an acoustic liner coupled to the second surface of the panel. The acoustic liner may have a panel-facing surface configured to couple to the second surface of the panel and a sound-absorbing surface configured to face toward the point. The sound-absorbing surface of the acoustic liner may be configured to define a convex curved arc relative to the point. 
     In some embodiments, the shield may further comprise a first side panel configured to be removably coupled to a first end of the panel, and a second side panel configured to be removably coupled to a second end of the panel. The panel, the first side panel, and the second side panel may be positioned around the point. 
     In some embodiments, the shield may further comprise a first side acoustic liner coupled to the first side panel and a second side acoustic liner coupled to the second side panel. The first side acoustic liner may have a surface that is bowed and configured to define a convex curved arc relative to the point. The second side acoustic liner may have a surface that is bowed and configured to define a convex curved arc relative to the point. 
     There exist a plurality of advantages of the present disclosure arising from the various features of the method, apparatus, and system described herein. It will be noted that alternative embodiments of the method, apparatus, and system of the present disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may readily devise their own implementations of the method, apparatus, and system that incorporate one or more of the features of the present invention and fall within the spirit and scope of the present disclosure as defined by the appended claims.