Abstract:
Electronic percussion instruments with enhanced playing areas and methods and systems for generating electrical signals in response to impacts to a playing surface are disclosed. A semi-permeable playing surface covering an acoustic noise reducing cavity of an electronic percussion instrument may receive an impact within a predefined impact region, and an electrical signal may be generated in response by an electromechanical sensor that senses the impact. In many instances, the generated electrical signal may be configured to be equivalent in magnitude to any other electrical signal generated by the electromechanical sensor, in response to any other received impact within the same predefined impact region.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims the benefit of priority of U.S. Provisional Application No. 61/979,419, filed Apr. 14, 2014, entitled “ELECTRONIC PERCUSSION INSTRUMENT WITH ENHANCED PLAYING AREA,” the disclosure of which is expressly incorporated herein by reference in its entirety. 
    
    
     FIELD 
     The present disclosure relates generally to electronic percussion instruments with enhanced playing areas and methods and systems for generating electrical signals using the same. 
     BACKGROUND AND DESCRIPTION 
     Traditionally, electronic percussion instruments (e.g., electronic drums) comprise a head (e.g., playing surface), composed of mesh, Mylar, or rubber material, attached to a housing (i.e., shell or cavity) and one or more sensors. The playing surface is usually made of a thin mesh (woven material), Mylar, or rubber material, and has an inferior end (i.e., bottom side) and a superior end (i.e., top side). The sensor typically comprises a flexible cushion material that is in contact with the inferior end of the playing surface mounted in the center of the drum, and an electromechanical transducer (piezoelectric transducer) positioned between the flexible cushion material and a supporting structure that is attached to the inner shell of the electronic percussion instrument. The supporting structure is generally a thin rigid material that is used to support the sensor. 
     Electronic percussion instruments are designed to transfer vibrations, induced by a user striking the superior end of a playing surface, to a flexible cushion material that is coupled to an electromechanical transducer that generates electrical signals in response to vibrations. These solutions are designed to give a varying electrical signal that can be interpreted by a drum module to determine how hard the surface was struck (i.e., magnitude). In some embodiments, a drum module can determine the magnitude and/or the location of the strike. The magnitude of the electrical signal (i.e., the amplitude of the velocity and/or force of the electrical signal) is determined by the shape, size, and location of the flexible cushion material, the sensor, and components (e.g., sensor plate) within the sensor. It is also determined by the location of the superior end of the playing surface that has been struck. Some modules may use the location and magnitude information to play different sounds or alterations to the current sound. 
     In many electronic percussion instruments, the flexible cushion material has a frustoconical shape, and the area of the flexible cushion material is considerably smaller than the entire area of the playing surface. The flexible cushion material is usually located in the center of the shell, and the superior end of the flexible cushion material is in contact with the inferior end of the playing surface. In such an orientation, a strike to the center of the superior end of the playing surface just above the flexible cushion material will cause the electromechanical transducer to generate an electrical signal with a magnitude that is greater than the magnitude of a signal corresponding to a strike further away from the center of the playing surface. Therefore, the sensitivity (i.e., magnitude of an electrical signal generated by an electromechanical transducer in response to a strike to a playing surface) is greater in the middle of the playing surface, as opposed to an area between the center and the perimeter of the playing surface. Thus, the area of the playing surface with the greatest sensitivity (i.e., sweet spot) is the area directly above the flexible cushion material. In most modern electronic percussion instruments, the area of the flexible cushion material is very small, thereby requiring a user to strike the superior end of the playing surface directly above the cushion material in order to generate a certain consistent sound. This design is appropriate for advanced users who are familiar with the sensitivity of a playing surface. However, novice and/or beginning users who are unfamiliar with the different areas of the playing surface, or have a lower degree of control or playing technique, have a harder time locating the sweet spot consistently. Existing designs make it difficult for novices and beginners to determine which area(s) of the playing surface should be struck in order to produce different sounds consistently. 
     An alternative design may enable a user to adjust the area of the sweet spot, thus enabling an electronic percussion instrument to reproduce a similar sound across a larger area of the playing surface. Multiple flexible cushion materials and electromechanical transducers of varying shapes and sizes can be used to adjust (i.e., increase or decrease) the area of sensitivity, thereby enabling an electronic percussion instrument to generate the same sound when a user strikes a portion of a playing surface corresponding to the adjusted area of sensitivity. By increasing the sweet spot, a user can strike the playing surface in a location that is not exactly at the center of the playing surface, and the electronic percussion instrument will produce the same sound that would be produced if the user struck the center of the playing surface. Conversely, as a user becomes more proficient at striking the playing surface in a sweet spot of a larger area, the user can reduce the area of the sweet spot thereby enabling a user to focus on striking different areas of a playing surface that correspond to an electronic percussion instrument producing different sounds. 
     Existing electronic percussion instruments are designed to generate differences in sensitivity levels across a playing surface due to the central location of a single flexible cushioning material. The present disclosure describes an electronic percussion instrument that can enable a user to adjust the differences in sensitivity levels across a playing surface, as well as maintain a constant sensitivity level across the entire playing surface. 
     SUMMARY 
     In one disclosed embodiment, a method for generating an audio signal from an electronic percussion instrument using a semi-permeable playing surface, noise reducing acoustic cavity, and electromechanical sensor is disclosed. The method comprises receiving an impact to the playing surface covering an acoustic cavity of the electronic percussion instrument, and transferring the impact to the shock absorbing posts that are communicatively coupled to the playing surface. The method further comprises transferring the impact received at the shock absorbing posts to the plate that is communicatively coupled to the shock absorbing posts, transferring the impact received at the plate to the electromechanical transducer that is communicatively coupled to the plate, and generating an audio signal, in response to the received impact, at the electromechanical transducer that is equivalent to the magnitude of the impact. 
     In another disclosed embodiment, an electronic percussion instrument is provided. The electronic percussion instrument includes an acoustic noise reducing cavity, a semi-permeable playing surface comprising connected strands of ductile material configured to cover the acoustic noise reducing cavity, and an electromechanical sensor configured to sense an impact to the semi-permeable playing surface. The electromechanical sensor is configured to sense an impact received within a predefined impact region of the semi-permeable playing surface, and to generate an electrical signal associated with the sensed impact, wherein the generated electrical signal is equivalent in magnitude to any other electrical signal generated by the sensor in response to any other received impact within the predefined impact region. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating an exemplary electronic percussion instrument system for producing a percussion sound, consistent with some of the embodiments of the present disclosure. 
         FIG. 2  is an exemplary image of the outside of an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 3  is an exemplary image of the inside of an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 4  is an exemplary image of a cross-sectional view of an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 5  is an exemplary image of a playing surface on an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 6  is an exemplary image of a sensor, consistent with some of the embodiments of the present disclosure. 
         FIG. 7  is a diagram illustrating an exemplary cross-sectional view of a sensor inside an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 8  is an exemplary image of an overhead view of a plate with shock absorbing posts superimposed on a sensor inside an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 9  is a diagram illustrating an exemplary cross-sectional view of two sensors inside an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 10  is an exemplary image of an overhead view of two vertically cascaded plates affixed to two sets of shock absorbing posts, and a potentiometer inside an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 11  is an exemplary image of an overhead view of two non-overlapping concentric plates affixed to two sets of shock absorbing posts, and a potentiometer, inside an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 12  is an exemplary image of the inside of an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 13  is an exemplary image of the superior end of a sensor in contact with the inferior end of a playing surface on an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 14  is an exemplary image of an overhead view of the inside of an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 15  is an exemplary image of an overhead view of a playing surface on an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 16  is an exemplary image of an overhead view of impact locations on a playing surface of an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 17  is an exemplary image of an overhead view of an inner and outer sensor inside an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 18  is an exemplary image of an overhead view of electrical wires connected to a sensor inside an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 19  is an exemplary image of the outside of an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 20  is an exemplary image of an overhead view of impact locations on a playing surface of an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 21  shows a circular diagram illustrating an overhead view of a sensor inside an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 22  shows a circular diagram illustrating an overhead view of two sensors inside an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 23  is an exemplary image of a sensor inside an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
         FIG. 24  is an exemplary image of two sensors inside an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure relates generally to methods and systems for generating acoustic, synthetic, and electronic drum sounds with the same timbre and/or intensity when a playing surface of an electronic percussion instrument is struck within a predefined area. In some embodiments, a voice or synthesized sound can be generated when a user strikes the playing surface. When a user, such as a musician, is not familiar with a playing surface of a particular electronic percussion instrument, he/she usually has to spend time either tuning the electronic percussion instrument, or learning about the different areas of the playing surface that should be struck in order to generate—particular sounds. A musician can therefore spend a considerable amount of time tuning a playing surface on an electronic percussion instrument in order to generate a sound with a certain timbre. An experienced musician can adjust the settings on an electronic percussion instrument quickly, but a beginner or even an intermediate musician might not be familiar enough with the settings, thereby requiring hours, or even days of learning in order to appropriately adjust the settings. Beginners also might not have the required skills or technique to consistently strike the proper area of the playing surface, thus requiring an electronic percussion instrument that can reproduce the same sound regardless of where a user strikes the playing surface. An electronic percussion instrument with a playing surface that can be struck in any location and generate a sound with the same timbre and/or intensity, shifts the responsibility of tuning an electronic percussion instrument from the musician to the electronic percussion instrument itself. An electronic percussion instrument with this feature enables a musician to spend more time learning how to play an electronic percussion instrument instead of adjusting the settings in order to produce an appropriate sound. 
     Methods and systems described herein enable electronic percussion instruments to generate a similar sound when a user strikes multiple regions of a playing surface of an electronic percussion instrument with a certain force. In general, the disclosure utilizes novel sensors that can be comprised of smart materials that may be combined and oriented with respect to one another in certain arrangements to increase or decrease the effective surface area of a playing surface of an electronic instrument over which the electronic percussion instrument can produce sounds that are the same. 
     Electronic percussion instruments disclosed herein may comprise a playing surface composed of one or more mesh, Mylar, and/or other elastic materials that reduce acoustic sounds within the electronic percussion instrument, when a user strikes the playing surface. A playing surface composed of mesh material can be woven in one or more different orientations. Electronic percussion instruments disclosed herein further comprise sensors comprising one or more shock absorbing materials and transducers, and a shell that may contain an anechoic chamber for reducing reverberations from acoustic waves generated by a playing surface when a user strikes the playing surface. 
     Sensors disclosed herein may be composed of one or more flexible shock absorbing materials, rigid plates, and/or electromechanical transducers that may be in contact with a playing surface of an electronic percussion instrument. The sensors may convert vibrations within a playing surface, induced by an impact to the playing surface, to an electrical signal that can be used by an electronic drum module to generate a musical tone or sound. Depending on the size, shape, and orientation of a sensor, an electromechanical transducer can generate similar or exactly the same electrical signal for impacts to certain predefined regions of a playing surface. 
     In some embodiments, components of a sensor may be arranged such that the magnitude of electrical signals generated by an electromechanical transducer in response to impacts of the same force across a playing surface is different at each location a user strikes a playing surface. This embodiment can enable a user to experience what it is like to play on an acoustic drum, because each point on the playing surface of an acoustic drum produces a unique acoustic sound. 
     In other embodiments, components of a sensor may be arranged such that the magnitude of electrical signals generated by an electromechanical transducer is approximately the same in response to impacts of the same force across a predefined area of a playing surface that does not encompass the entire playing surface. Such an embodiment can enable an electromechanical transducer to generate electrical signals of similar magnitude for impacts of the same force to these regions. Such an embodiment can help an intermediate or novice user learn which portions of a playing surface should be struck in order to induce an electromechanical transducer to generate a certain electrical signal. 
     In yet other embodiments, components of a sensor may be arranged such that the magnitude of electrical signals generated by an electromechanical transducer can be exactly the same in response to impacts of the same force, across an entire playing surface. Such an embodiment can enable an electromechanical transducer to generate electrical signals of exactly the same magnitude for impacts of the same force regardless of where a user strikes a playing surface. Such embodiments may help a user to focus on playing an electronic percussion instrument, rather than tuning it to generate a particular sound. 
     In yet another embodiment, one or more sensors may be used such that the magnitude of the electrical signals generated by one or more electromechanical transducers can be adjusted to be exactly the same, equivalent (i.e., similar but not exactly the same), or very different depending on a user&#39;s preference. If sensors are oriented concentrically, a user may decide to adjust the sensors such that the magnitude of the sensors increases from the center of the electronic percussion instrument to the edge of the electronic percussion instrument, or vice versa. Alternatively, a user may adjust the sensors such that any permutation and/or combination of sensitivity levels can be implanted. For example, two sensors may have exactly the same sensitivity level, but may be separated by a sensor that has a different sensitivity level. A user is thereby able to customize the magnitude of an electrical signal, and therefore the timbre of a musical tone, by adjusting the sensitivity of the sensors. 
     Furthermore, the present disclosure may be characterized by an electronic percussion instrument system that detects a strike to a playing surface of an electronic percussion instrument, generates a corresponding electrical signal that can be used to generate a musical tone, or sound based on certain properties of the electrical signal, and outputs the musical tone, or sound to a speaker or other output device. 
     The following detailed description refers to the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the following description to refer to the same or similar parts. While several example embodiments are described herein, modifications, adaptations, and other implementations are possible. For example, substitutions, additions, or modifications may be made to the components illustrated in the drawings. The example methods described herein may be modified by removing, substituting, reordering, or adding steps to the disclosed methods. Accordingly, the foregoing general description and the following detailed description are exemplary only, and are not limiting. 
     In addition, numerous specific details are set forth in order to provide a thorough understanding of the exemplary embodiments described herein. However, it will be understood by those of ordinary skill in the art that these embodiments may be practiced without all the specific details. Furthermore, well-known methods, procedures and components have not been described in detail so as not to obscure the exemplary embodiments described herein. 
     A single form of a term in this disclosure includes the terms&#39; plural form, and vice versa. The indefinite article (a or an) and the definite article (the), when used in the specification and claims, is meant to include one or more of the objects, activities or steps than it might qualify, unless otherwise expressly indicated to the contrary. For example, “a” sensor can be one or more than one sensor. 
       FIG. 1  shows a diagram illustrating an exemplary electronic percussion instrument system for producing percussion sounds, consistent with the embodiments of the present disclosure. Electronic percussion instrument system  101  can be comprised of electronic percussion instruments  103  and drum module  105 . Electronic percussion instruments  103  may comprise one or more electronic percussion instruments as described herein. 
     Drum module  105  may be a device that receives electrical signals from percussion instruments  103 , and output one or more sounds. Drum module  105  may include at least one processor, which controls the operation of drum module  105 . Processors included in drum module  105  may be, for example, a single microprocessor, multiple microprocessors, field programmable gate arrays (FPGAs), or digital signal processors (DSPs) capable of executing particular sets of instructions. The instructions executed on the processors can include instructions that enable drum module  105  to produce a set of sounds that are selectable by a user to be triggered when a user strikes electronic percussion instruments  103 . In some embodiments, the instructions can be preprogrammed sounds or tones that can be edited or modified by a user. In other embodiments, a user can create the instructions. 
       FIG. 2  is an exemplary image of the outside of an electronic percussion instrument, consistent with some of the embodiments of the present disclosure. Electronic percussion instrument  201  may be comprised of playing surface  203 , tuning rod  205 , shell  207 , rim  209 , and nut boxes  211 . Nut boxes  211  may have a tapped hole with a threaded groove configured to receive tuning rods  205  that are screwed into nut boxes  211 . Tuning rods  205  may be screwed into nut boxes  211  to secure playing surface  203  and rim  209  to shell  207 . 
     Playing surface  203  may be composed of materials such as mesh, Mylar, or rubber. In some embodiments, playing surface  203  may generate no sound when struck by a user. In other embodiments, playing surface  203  may generate a variety of sounds when struck by a user. Playing surface  203  may be an elastic membrane of uniform thickness attached to rim  209 . The elastic membrane can comprise a plurality of strands composed of ductile material. The strands can be woven together to form a lattice structure. The lattice structure can comprise a plurality of lattice cells, wherein each lattice cell can comprise a plurality of intersecting strands of ductile material. The area between the internal edges of the intersecting strands can form an opening through which mechanical waves (e.g., sound waves), induced by a user striking the elastic membrane, can be transferred to the inside of electronic percussion instrument  201 . In some embodiments, the strands of the lattice cell can be woven together in such a way so as to reduce the number of sound waves transferred to the inside of electronic percussion instrument  201 . For example, increasing the number of intersecting strands in a lattice cell can reduce the intensity of the sound waves transferred to the inside of electronic percussion instrument  201 , while preserving the same reverberation properties (i.e., restoring forces) of an acoustic drum playing surface. 
     Tuning rods  205  may be rotated clockwise or counter clockwise to increase or decrease the tension of playing surface  203 . In some embodiments, increasing or decreasing the tension in playing surface  203  adjusts the pitch and resonance of electronic percussion instrument  201 . For example, increasing tension in playing surface  203  may result in playing surface  203  generating smaller vibrations when a user strikes the surface, thereby producing smaller resonances. Conversely, when tension in playing surface  203  is decreased, playing surface  203  may generate larger vibrations thereby producing larger resonances. Therefore, in some embodiments, adjusting the tension in playing surface  203  may change the output signal generated by speaker a speaker connected to drum module  105 , as a result of a user striking playing surface  203 . 
     In other embodiments an output signal generated by a speaker, as a result of a user striking playing surface  203 , can be changed by hardware and software components within drum module  105 . Drum module  105  can generate an electronic tone, when a user strikes playing surface  203 , that corresponds to an electrical signal that can be generated by drum module  105 , after adjusting the tension in playing surface  203 . For instance, if playing surface  203  is adjusted to a certain tension level, and a user strikes playing surface  203 , drum module  105  can output an electronic tone to a speaker. Alternatively, the tension level in playing surface  203  might not be adjusted, and drum module  105  may output the same electronic tone to a speaker when a user strikes playing surface  203 , by modifying the signal received from electronic percussion instrument  201 . In some embodiments, drum module  105  may modify a signal received from electronic percussion instrument  201 , and output an electrical signal to a speaker that corresponds to increasing or decreasing the tension in playing surface  203 . Therefore, drum module  105  may generate a plurality of tones corresponding to different tensions in playing surface  203  without the tensions in playing surface  203  being adjusted. 
       FIG. 3  is an exemplary image of the inside of an electronic percussion instrument, consistent with some embodiments of the present disclosure. Electronic percussion instrument  301  may be comprised of one or more flanges  303  extending from sensor enclosure  305  to the perimeter of the interior of shell  307 . Flanges  303  may be composed of plastic, metal, a hybrid of plastic and metal, and/or other materials. In some embodiments the orientation and quantity of flanges  303  may modify the acoustic waves generated by a user striking a playing surface (not shown). Flanges  303  may be used to strengthen electronic percussion instrument  301 , and to absorb sound waves, thereby reducing echoes produced by the inside of electronic percussion instrument  301  when a user strikes a playing surface. In some embodiments, flanges  303  may be used to create an anechoic chamber (i.e., echo-free chamber) within electronic percussion instrument  301 . Therefore, the quantity and orientation of flanges  303  may create an echo-free chamber, thereby enabling electronic percussion instrument  301  to produce no sound when a user strikes a playing surface. 
     Sensor enclosure  305  may comprise sensor  309 , dampening material  311 , and plate  313 . Sensor  309  can be affixed to dampening material  311 , and dampening material  311  can be affixed to plate  313 . Dampening material  311  may be composed of rubber or other pliable material. Plate  313  may be metal or plastic, and may be affixed to the bottom of the interior of shell  307 . Sensor  309  may be affixed to dampening material  311  by one or more screws, bolts, binding chemicals, and/or any combination of the aforementioned. Dampening material  311  may be affixed to plate  313  by one or more screws, bolts, binding chemicals, and/or any combination of the aforementioned. Plate  313  may be affixed to the bottom of the interior shell  307  by one or more screws, bolts, binding chemicals, and/or any combination of the aforementioned. The exterior  315  of sensor enclosure  305  can reflect acoustic waves away from sensor  309  when a user strikes a playing surface (not shown). Sensor enclosure  305  may reflect acoustic waves away from sensor  309 , so that sensor  309  does not absorb any acoustic waves generated when a user strikes a playing surface. Absorption of acoustic waves by sensor  309  can affect the ability of sensor  309  to sense vibrations from a playing surface when vibrations from a playing surface are transferred to sensor  309  by shock absorbing posts  317 . Sensor enclosure  305  may have a conical, square, triangular, and/or other shape that maximizes the reflectance of acoustic waves away from sensor  309 . In some embodiments the shape of sensor enclosure  305  may be determined by the magnitude (e.g., amplitude, phase, frequencies, and/or velocity) of the acoustic waves reflected by the interior of shell  307 , when a user strikes a playing surface. The thickness of sensor enclosure  305  may be determined by the magnitude of acoustic waves generated by the interior of shell  307 . For instance, the thickness of enclosure  305  may be determined by the frequencies of acoustic waves that can be generated by the interior of shell  307  after a user has struck a playing surface. The thickness of sensor enclosure  305  may increase as the range of frequencies that may be generated by the interior of shell  307  increases. For example, sensor enclosure  305  can be a first thickness corresponding to a first frequency produced by the interior of shell  307 , or a second thickness, greater than the first thickness, if a second frequency is greater than the first frequency. 
       FIG. 4  is an exemplary image of a cross-sectional view of an electronic percussion instrument, consistent with some embodiments of the present disclosure. The inferior end of playing surface  401  may be in contact with the superior end of shock absorbing posts  403 . When a user strikes playing surface  401 , the vibrations generated by playing surface  401  may be transferred to shock absorbing posts  403 . 
       FIG. 5  is an exemplary image of a playing surface on an electronic percussion instrument, consistent with some embodiments of the present disclosure. Playing surface  501  may be composed of a mesh, Mylar, rubber, and/or other flexible material. The inferior end of playing surface  501  may be in contact with the superior end of shock absorbing posts (not shown). 
       FIG. 6  is an exemplary image of a sensor, consistent with some embodiments of the present disclosure. Sensor  601  may be composed of shocking absorbing posts  603 , plate  605 , and electromechanical transducer  607 . The superior end of shock absorbing posts  603  may be in contact with the inferior end of a playing surface (not shown). When a user strikes a playing surface, the vibrations generated in the playing surface may be transferred to shock absorbing posts  603 . The vibrations in shock absorbing posts  603  may cause plate  605  to vibrate, which may cause electromechanical transducer  607  to vibrate. Electromechanical transducer  607  may generate an electrical signal in response to the vibrations induced. 
     Electromechanical transducer  607  may generate different electrical signals depending on the force with which a user strikes a playing surface. For example, if a playing surface is struck in the center of shock absorbing posts  603  with a first force that is greater than a second force, electromechanical transducer  607  may produce a first electrical signal that has a greater velocity than a second electrical signal. In some embodiments, the amplitude of a first electrical signal may be greater than the amplitude of a second electrical signal, if the force corresponding to the first electrical signal is greater than the force corresponding to the second electrical signal. In other embodiments, the phase of a first electrical signal can be different (e.g., larger or smaller) than the phase of a second electrical signal, if the force corresponding to the first electrical signal is greater than the force corresponding to the second electrical signal. 
     Electromechanical transducer  607  may generate different electrical signals depending on the location of a strike on a playing surface. The area of plate  605  may be equivalent to the area of electromechanical transducer  607 . In such a case, if a user strikes any area of a playing surface within shock absorbing posts  603 , with the same force, electromechanical transducer  607  may produce the same electrical signal. For instance, if a playing surface is struck directly above shock absorbing post  603   a , electromechanical transducer  607  may produce an electrical signal with a magnitude (e.g., size of the velocity) that is equivalent to the magnitude associated with an electrical signal that is produced when the playing surface is directly struck above shock absorbing post  603   b . Therefore, in some embodiments, the velocity of an electrical signal produced by electromechanical transducer  607  is the same whenever a playing surface is struck within the area directly above plate  605 . 
     If a playing surface is struck in an area that is not directly above plate  605 , the magnitude of an electrical signal generated by electromechanical transducer  607  may not be the same as the magnitude of an electrical signal corresponding to a playing surface struck directly above plate  605 . However in some embodiments, it is possible for electromechanical transducer  607  to produce electrical signals of the same magnitude, independent of where a user strikes a playing surface. For example, electromechanical transducer  607  may generate a first electrical signal with a first velocity, in response to a first force applied to the center of shock absorbing posts  603 , that is equal to a second velocity associated with a second electrical signal corresponding to a second force applied to the circumferential edge of the playing surface, if the second force is greater than the first force. Therefore, the force required to generate an electrical signal with the same velocity may increase as the radial distance between the center of shock absorbing posts  603  and the circumferential edge where a user applies a force to a playing surface increases. 
       FIG. 7  shows a diagram illustrating an exemplary cross-sectional view of a sensor inside an electronic percussion instrument, consistent with some embodiments of the present disclosure. Electronic percussion instrument  701  may be comprised of playing surface  703 , shock absorbing posts  705 , plate  707 , electromechanical transducer  709 , dampening material  711 , and structural body  713 . The superior end of shock absorbing posts  705  may be in contact with the inferior end of playing surface  703 . 
     Plate  707  may be composed of plastic, metal, and/or another hard/rigid material. The superior end of plate  707  may be in contact with the inferior end of shock absorbing posts  705 . Plate  707  may transfer vibrations, induced by a user striking playing surface  703 , to electromechanical transducer  709  via shock absorbing posts  705 . 
     Electromechanical transducer  709  may be a piezoelectric sensor comprised of a crystalline structure that may produce electrical signals in response to vibrations (e.g., strain or stress) within the crystalline structure. The superior end of electromechanical transducer  709  may be in contact with the inferior end of plate  707 . 
     Dampening material  711  can be composed of the same material that dampening material  311  is composed of, and may be used to dampen vibrations generated by forces applied by a user to playing surface  703 . Dampening material  711  can be used to prevent seismic and/or acoustic waves from being produced, within electronic percussion instrument  701 , that can perturb electrical signals generated by electromechanical transducer  709 . For example, when a user strikes playing surface  703 , dampening material  711  can reduce the impact of seismic and/or acoustic waves on electromechanical transducer  709  by absorbing seismic and/or acoustic waves reflected from the edges of electronic percussion instrument  701 . The superior end of dampening material  711  may be in contact with the inferior end of electromechanical transducer  709 . 
     Structural body  713  can be composed of plastic, metal, or another hard/rigid material. Structural body  713  can be used as a raised platform upon which the aforementioned components can be supported. The superior end of structural body  713  may be in contact with the inferior end of dampening material  711 , and the inferior end of structural body  713  can be in contact with the superior end of the inside of the bottom of electronic percussion instrument  701 . 
       FIG. 8  is an exemplary image of an overhead view of a plate with shock absorbing posts superimposed on a sensor inside an electronic percussion instrument, consistent with some embodiments of the present disclosure.  FIG. 8  illustrates how the shape and size of a plate as well as the quantity of shock absorbing posts can increase the sensitivity of a sensor. The inside of electronic percussion instrument  801  may be comprised of sensor  809  and shell  807 . Plate  803  can be a plate with shock absorbing posts, superimposed on sensor  809 , that can have a greater area than plate  813 . Plate  803  illustrates how a plate of a larger area can increase the area over which a user can strike a playing surface (not shown), such that sensor  809  generates electrical signals of equivalent magnitude (sensitivity). 
     Sensor  809  may comprise shock absorbing posts  811 , plate  813 , and electromechanical transducer  815 . Plate  813  can be used to transfer vibrations, induced by a user striking a playing surface (not shown), to electromechanical transducer  815  via shock absorbing posts  811 . The superior end of electromechanical transducer  815  can be in contact with the inferior end of plate  813 . 
     Shock absorbing posts  805  may be perpendicular to the cross-sectional area of plate  803 . The inferior end of shock absorbing posts  805  can be in contact with plate  803 . Shock absorbing posts  805  can transmit a received impact from a playing surface (not shown) to plate  803 , and plate  803  can transmit the received impact to electromechanical transducer  815 . 
     Shell  807  may be made of the same material, have the same components (e.g., flanges  303 ), and same structure as shell  307 . 
     If plate  803  is used instead of plate  813 , then the area over which a user may strike a playing surface to generate electrical signals of equivalent magnitude can be increased. For instance, if shock absorbing post  805   a  is a greater radial distance from the center of electromechanical transducer  815  than shock absorbing post  811   a , then a strike of equal force, within a concentric area of a playing surface between shock absorbing post  805   a  and  811   a  can result in electromechanical transducer  815  generating an electrical signal with a magnitude equivalent to a magnitude of an electrical signal corresponding to a strike within a concentric area of a playing surface between the center of electromechanical transducer  815  and shock absorbing post  811   a.    
       FIG. 9  shows a diagram illustrating an exemplary cross-sectional view of two sensors inside an electronic percussion instrument, consistent with some embodiments of the present disclosure. Electronic percussion instrument  901  may comprise playing surface  903 , first sensor  905 , second sensor  907 , and structural body  909 . First sensor  905  may comprise shock absorbing posts  905   a , plate  905   b , and electromechanical transducer  905   c . Second sensor  907  may comprise shock absorbing posts  907   a , plate  907   b , and electromechanical  907   c . Electronic percussion instrument  901  may further comprise dampening material  911 . 
     Playing surface  903  may be composed of the same material as playing surface  703 . Shock absorbing posts  905   a  and  907   a  may be composed of the same material as shock absorbing posts  705 . The superior end of shock absorbing posts  905   a  and  907   a  may be in contact with the inferior end of playing surface  903 . 
     Plates  905   b  and  907   b  may be composed of the same material as plate  707 . The superior end of plate  905   b  and  907   b  may be in contact with the inferior end of shock absorbing posts  905   a  and  907   a.    
     Electromechanical transducers  905   c  and  907   c  may be composed of the same crystalline piezoelectric material as electromechanical transducer  709 . The superior end of electromechanical transducers  905   c  and  907   c  may be in contact with the inferior end of plate  905   b  and  907   b  respectively. 
     Dampening material  911  may be composed of the same dampening material as dampening material  711 . The superior end of dampening material  911  can be in contact with the inferior end of electromechanical transducer  905   c  and can surround electromechanical transducer  907   c.    
     Structural body  909  may be composed of the same material as structural body  713 . The superior end of structural body  909  can be in contact with the inferior end of dampening material  911 , and the inferior end of structural body  909  can be in contact with the superior end of the inside of the bottom of electronic percussion instrument  901 . 
     First sensor  905  and second sensor  907  can perform the same function as sensor  601 . That is, when a user strikes playing surface  903 , first sensor  905  or second  907  can generate an electrical signal with a magnitude that may be proportional to the force exerted on playing surface  903  above shock absorbing posts  905   a  and  907   a.    
     Electromechanical transducer  905   c  and  907   c  can produce electrical signals with similar magnitudes, independent of where a user strikes a playing surface. If a user strikes an area of playing surface  903  above plate  905   b  or  907   c  with equal force, the electrical signal generated by electromechanical transducer  905   c  can have a magnitude equivalent to the magnitude of an electrical signal generated by electromechanical transducer  907   c . This can enable electronic percussion instrument  901  to generate a more consistent electrical signal regardless of where playing surface  903  is struck. Therefore the burden on the user, of pinpointing, and striking, a specific location on a playing surface in order to get electronic percussion instrument  901  to generate a certain electrical signal is lifted. 
     Even though electromechanical transducer  907   c  and  905   c  can produce electrical signals with equivalent magnitudes, the magnitudes may not be exactly equal. However, changing the shape, size, and orientation of the sensors can enable electronic percussion instrument  901  to produce electrical signals that have magnitudes that are exactly equal regardless of where a user strikes a playing surface. In some embodiments, a plurality of cascading sensors can be added to electronic percussion instrument  901 , to create a uniform sensitivity level across the entire area of playing surface  903 . Therefore, additional sensors can be added to electronic percussion instrument  901 , to create additional segments of playing surface  903  that may be directly in contact with a single sensor. 
       FIG. 10  is an exemplary image of an overhead view of two plates affixed to two sets of shock absorbing posts, and a potentiometer inside an electronic percussion instrument, consistent with some embodiments of the present disclosure. The inside of electronic percussion instrument  1001  may comprise plate  1003  and  1005 , shock absorbing posts  1003   a  and  1005   a , shell  1007 , and potentiometer  1009 . Plate  1003  and  1005  may have a square shape. In other embodiments plate  1003  and  1005  may have a circular shape, and/or other shape. Shock absorbing posts  1003   a  and  1005   a  may be perpendicular to the cross-sectional area of plate  1003  and  1005  respectively. The superior end of shock absorbing posts  1003   a  and  1005   a  may be in contact with a playing surface (not shown). The inferior end of shock absorbing posts  1003   a  may be in contact with the plate  1003 , and shock absorbing posts  1005   a  may be in contact with plate  1005 . If a user strikes the playing surface within an area above plate  1003 , shock absorbing post  1003   a  may transmit the received impact from the playing surface to plate  1003 . And plate  1003  may transmit the received impact to an electromechanical transducer (not shown) in contact with plate  1003 . If a user strikes the playing surface within an area above plate  1005 , shock absorbing posts  1005   a  may transmit the received impact to plate  1005 . And plate  1005  may transmit the received impact to an electromechanical transducer (not shown) in contact with plate  1005 . The inferior end of plate  1003  may be in contact with the superior end of an electromechanical transducer. The inferior end of plate  1005  may be in contact with the superior end of another electromechanical transducer. 
     The area of plate  1003  can be greater than the area of the electromechanical transducer (not shown) that is in contact with it. If the area of plate  1003  is greater than the area of the electromechanical transducer affixed to it, then the magnitude of an electrical signal produced by the electromechanical transducer can be equivalent to the magnitude of an electrical signal generated by the electromechanical transducer when a user strikes any area of the playing surface, with the same force, above plate  1003 . Similarly, the area of plate  1005  can be greater than the area of the electromechanical transducer (not shown) that is in contact with it. If the area of plate  1005  is greater than the area of the electromechanical transducer affixed to it, then the magnitude of an electrical signal produced by the electromechanical transducer can be equivalent to the magnitude of an electrical signal generated by the electromechanical transducer when a user strikes any area of the playing surface, with the same force, between plate  1003  and plate  1005 . 
     Potentiometer  1009  can be a variable resistor (e.g., rheostat) that can be used to adjust the sensitivity level of the electromechanical transducer affixed to the bottom of plate  1003  and the electromechanical transducer affixed to the bottom of plate  1005 . Adjusting the variable resistor can correspond to increasing or decreasing the resistance. In some embodiments, the sensitivity level of the electromechanical transducer affixed to the bottom of plate  1003  may be greater than the sensitivity level of the electromechanical transducer affixed to the bottom of plate  1005 . Therefore, an electrical signal produced by an electromechanical transducer affixed to the bottom of plate  1003  may have a greater magnitude than an electrical signal produced by an electromechanical transducer affixed to the bottom of plate  1005 . In other embodiments, the sensitivity level of an electromechanical transducer affixed to the bottom of plate  1005  may be greater than the sensitivity level of an electromechanical transducer affixed to the bottom of plate  1003 . 
     In yet other embodiments, potentiometer  1009  can be adjusted so that the sensitivity levels of an electromechanical transducer affixed to  1003  and an electromechanical transducer affixed to  1005  are the same. Thus, an electromechanical transducer affixed to plate  1003  and an electromechanical transducer affixed to plate  1005  can produce electrical signals with magnitudes that are exactly the same when a user strikes any location of the playing surface. 
     In some embodiments, an electronic percussion instrument may comprise sensors (plates, shock absorbing posts, and electromechanical transducer) that can be oriented in such a way that they are not cascaded vertically as illustrated in  FIG. 9  and  FIG. 10 . 
       FIG. 11  is an exemplary image of an overhead view of two non-overlapping concentric plates affixed to two sets of shock absorbing posts, and a potentiometer, inside an electronic percussion instrument, consistent with some embodiments of the present disclosure. 
     The electronic percussion instrument  1101  may comprise plate  1103  and  1105 , shock absorbing posts  1103   a  and  1105   a , shell  1107 , and potentiometer  1109 . Plate  1103  and  1105  may have a ring shape. In other embodiments plate  1103  and  1105  may have other shapes. Shock absorbing posts  1103   a  and  1105   a  may be perpendicular to the cross-sectional area of plate  1103  and  1105  respectively. The superior end of shock absorbing posts  1103   a  and  1105   a  may be in contact with a playing surface (not shown). The inferior end of shock absorbing posts  1103   a  can be in contact with the plate  1103 , and shock absorbing posts  1105   a  can be in contact with plate  1105 . If a user strikes a playing surface within an area above plate  1103 , shock absorbing posts  1103   a  may transmit the received impact from a playing surface to plate  1103 . And plate  1103  may transmit a received impact to an electromechanical transducer (not shown) in contact with plate  1103 . If a user strikes a playing surface within an area above plate  1105 , shock absorbing posts  1105   a  may transmit a received impact to a playing surface to plate  1105 . And plate  1105  can transmit a received impact to an electromechanical transducer (not shown) in contact with plate  1105 . The inferior end of plate  1103  can be in contact with the superior end of a ring shaped electromechanical transducer that is equal in circumference to the electromechanical transducer. If a user strikes a playing surface (not shown) above plate  1103 , the impact can be transferred to an electromechanical transducer (not shown) that can create an electrical signal. The inferior end of plate  1105  can be in contact with the superior end of another circular electromechanical transducer. If a user strikes a playing surface above plate  1105 , the impact can be transferred to an electromechanical transducer that can create an electrical signal. 
     Potentiometer  1109  can be the same as potentiometer  1009 . 
     In some embodiments, sensors can be added and/or removed without having to disturb other sensors in the electronic percussion instrument. If sensors are cascaded vertically, replacing or removing a sensor that is not on top, requires removing each sensor between the sensor that needs to be replaced and the sensor on top. Adding additional concentric sensors can increase the sensitivity of an electronic percussion instrument. 
     This is because each concentric sensor can comprise a greater number of shock absorbing posts whose superior ends are in direct contact with the inferior end of a playing surface. Increasing the number of concentric sensors increases the number of shock absorbing posts that are in contact with the playing surface, resulting in an increased ability of each electromechanical transducer associated with a corresponding concentric sensor to generate electrical signals with the same magnitudes when a user strikes any location of the playing surface. Each electromechanical transducer can have a superior end that can be in contact with the entire circumference of the inferior end of a concentric sensor plate that has shock absorbing posts along the entire circumference of its superior end. Therefore, when a user strikes any area of a playing surface, with the same force, the magnitude of an electrical signal generated by each electromechanical transducer can be exactly the same. Therefore in some embodiments it is possible for an electronic percussion instrument to create the exact same electrical signal regardless of where a user strikes the playing surface, if a plurality of concentric sensors is used. 
       FIG. 12  is an exemplary image of the inside of an electronic percussion instrument, consistent with some embodiments of the present disclosure. Electronic percussion instrument  1201  may comprise one or more flanges  1203  extending from sensor enclosure  1205  to the perimeter of the interior of shell  1207 . In some embodiments the orientation and quantity of flanges  1203  can modify the acoustic waves generated by a user striking a playing surface (not shown). Flanges  1203  can be used to strengthen electronic percussion instrument  301 , and to absorb sound waves, thereby minimizing echoes produced by the inside of electronic percussion instrument  1201 , when a user strikes a playing surface (not shown). In some embodiments flanges  1203  can be used to create an anechoic chamber (i.e., echo-free chamber) within electronic percussion instrument  1201 . Therefore the quantity and orientation of flanges  1203  can create an echo-free chamber thereby enabling electronic percussion instrument  1201  to produce no sound (i.e., no acoustic sound) within the interior of shell  1207 . This would enable a user to play electronic percussion instrument  1201  silently. In other embodiments, electronic percussion instrument  1201  might produce a sound when a user strikes a playing surface. 
     Sensor enclosure  1205  may comprise sensor  1209 , dampening material  1211 , and plate  1213 . Sensor  1209 , dampening material  1211 , and plate  1213  can be composed of the same materials as sensor  601 , dampening material  711 , and plate  707  respectively. Sensor  1209 , dampening material  1211 , and plate  1213  can have the same orientation within sensor enclosure  1205  as sensor  309 , dampening material  311 , and plate  313  within sensor enclosure  305 . 
     Sensor  1209  can have a quadrilateral shape. In some embodiments sensor  1209  can have a triangular, circular, or ring shape. 
       FIG. 13  is an exemplary image of the superior end of a sensor in contact with the inferior end of a playing surface on an electronic percussion instrument, consistent with some embodiments of the present disclosure. In some embodiments, the inferior end of a playing surface of an electronic percussion instrument can be made of a mesh material that can be in touch with the superior end of one or more shock absorbing posts. 
       FIG. 14  is an exemplary image of an overhead view of the inside of an electronic percussion instrument, consistent with some embodiments of the present disclosure. Electronic percussion instrument  1401  can be comprised of the same components and materials as electronic percussion instrument  301 . 
     Sensor enclosure  1405  can comprise sensor  1409 , dampening material  1411 , and plate  1413 . Sensor  1409 , dampening material  1411 , and plate  1413  can be composed of the same materials as sensor  601 , dampening material  711 , and plate  707  respectively. Sensor  1409 , dampening material  1411 , and plate  1413  can be arranged the same way sensor  309 , dampening material  311 , and plate  313  are arranged within sensor enclosure  305 . 
       FIG. 15  is an exemplary image of an overhead view of a playing surface on an electronic percussion instrument, consistent with some embodiments of the present disclosure. The inferior end of playing surface  1501  may be in contact with the superior end of an insulation material. When a user strikes playing surface  1501  the striking object generates vibrations in playing surface  1501 , which are transferred to an insulation material in contact with the inferior end of playing surface  1501 . 
       FIG. 16  is an exemplary image of an overhead view of impact locations on a playing surface of an electronic percussion instrument, consistent with some embodiments of the present disclosure. Playing surface  1601  can have four impact locations (outer impact location  1601   a , middle impact location  1601   b , middle impact location  1601   c , and center impact location  1601   d ). Each impact location represents different radii that correspond to different sensitivity levels across playing surface  1601 . 
     The sensitivity may be determined by measuring the velocity with which a user strikes playing surface  1601 . Drum module  105  may measure the velocity with which a user strikes playing surface  1601  by measuring oscillatory features of an electrical signal generated by an electromechanical transducer when a user strikes playing surface  1601 . Areas of playing surface  1601  that can induce an electromechanical transducer to generate electrical signals with higher velocities can have higher sensitivities. 
     In some embodiments, playing surface  1601  may be composed of a Mylar material and outer impact location  1601   a  can have a MIDI velocity range of 17-20, middle impact location  1601   b  can have a MIDI velocity range of 46-52, middle impact location  1601   c  can have a MIDI velocity range of 46-57, and center impact location  1601   d  can have a MIDI velocity range of 50-60. 
     In other embodiments, playing surface  1601  may be composed of a Mesh material. If playing surface  1601  is composed of a mesh material, outer impact location  1601   a  can have a MIDI velocity range of 17-22, middle impact location  1601   b  can have a MIDI velocity range of 17-29, middle impact location  1601   c  can have a MIDI velocity range of 36-46, and center impact location  1601   d  can have a MIDI velocity range of 50-60. 
       FIG. 17  is an exemplary image of an overhead view of an inner and outer sensor inside an electronic percussion instrument, consistent with some embodiments of the present disclosure. 
     Electronic percussion instrument  1701  may comprise shell  1703 , first sensor  1705 , and second sensor  1707 . First sensor  1705  may comprise shock absorbing posts  1705   a , plate  1705   b , and electromechanical transducer  1705   c . Second sensor  1707  may comprise shock absorbing posts  1707   a , plate  1707   b , and electromechanical transducer  1707   c.    
     Shock absorbing posts  1705   a  and  1707   a  may be composed of the same material that shock absorbing posts  705  are composed of. The superior end of shock absorbing posts  1705   a  and  1707   a  may be in contact with the inferior end of a playing surface (not shown). 
     The superior end of plate  1705   b  and  1707   b  may be in contact with the inferior end of shock absorbing posts  1705   a  and  1707   a.    
     The superior end of electromechanical transducer  1705   c  and  1707   c  may be in contact with the inferior end of plate  1705   b  and  1707   b  respectively. 
     First sensor  1705  and second sensor  1707  may perform the same function as sensor  601 . That is, when a user strikes a playing surface (not shown) that can be in contact with first sensor  1705  and second sensor  1707 , first sensor  1705  and/or second  1707  can generate an electrical signal with a magnitude that can be proportional to the force exerted on the playing surface above shock absorbing posts  1705   a  and/or  1707   a.    
     In some embodiments, plate  1705   b  can be larger and more shock absorbing posts can be used. Plate  1707   b  can be semicircular in some embodiments, and it can be a complete circle in other embodiments. 
     In some embodiments a potentiometer can be included to adjust the sensitivity between electromechanical transducer  1705   c  and  1707   c.    
     Electromechanical transducers  1705   c  and  1707   c  can have the same or different dimensions. For instance, in some embodiments the shape and orientation of sensors can determine the dimension of each sensor. For example, if sensors  1705  and  1707  are arranged concentrically and sensor  1705  is the inner sensor and sensor  1707  is the outer sensor, then the number of shock absorbing posts  1707   a  on plate  1707   b  and the circumference of electromechanical transducer  1707   c  can be greater than the number of shock absorbing posts  1705   a  on plate  1705   b  and the circumference of electromechanical transducer  1705   c , respectively. Therefore, because sensor  1707  can have a greater circumference than sensor  1705 , sensor  1707  can have different dimensions than sensor  1705 . 
       FIG. 18  is an exemplary image of an overhead view of electrical wires connected to a sensor inside an electronic percussion instrument, consistent with some embodiments of the present disclosure. 
     Electronic percussion instrument  1801  can comprise sensor  1803  and wires  1811 . Sensor  1803  can comprise shock absorbing posts  1805 , plate  1807 , and electromechanical transducer  1809 . Wires  1811  can be electrical wires attached to sensor  1803  for transmitting electrical signals to drum module  105 , in response to vibrations induced in sensor  1803  by a user striking a playing surface (not shown). 
       FIG. 19  is an exemplary image of the outside of an electronic percussion instrument, consistent with some embodiments of the present disclosure. 
     Electronic percussion instrument  1901  may comprise playing surface  1903 , tuning rod  1905 , rim  1907 , and nut boxes  1909 . Nut boxes  1909  may have a tapped hole with a threaded groove configured to receive tuning rods  1905  that can be screwed into nut boxes  1909 . Tuning rods  1905  may be screwed into nut boxes  1909  to secure playing surface  1903  to rim  1907 . 
       FIG. 20  is an exemplary image of an overhead view of impact locations on a playing surface of an electronic percussion instrument, consistent with some embodiments of the present disclosure. Playing surface  2003  can have four impact locations (outer impact location  2003   a , middle impact location  2003   b , middle impact location  2003   c , and center impact location  2003   d ). Each impact location represents different radii that correspond to different sensitivity levels across playing surface  2003 . 
     The sensitivity can be determined by measuring the velocity with which a user strikes playing surface  2003 . Drum module  105  can measure the velocity with which a user strikes playing surface  2003  by measuring oscillatory features of an electrical signal generated by an electromechanical transducer when a user strikes playing surface  2003 . Areas of playing surface  2003  that can induce an electromechanical transducer to generate electrical signals with higher velocities can have higher sensitivities. 
     Electronic percussion instrument  2001  may comprise playing surface  2003 , sensor  2005 , and sensor  2007 . Sensitivity levels associated with sensors  2005  and  2007  may be adjusted, with a potentiometer, so that areas on playing surface  2003  above sensor  2005  can be more/less sensitive than areas on playing surface  2003  above sensor  2007 . In some embodiments sensitivity levels can be exactly the same. 
     In some embodiments, outer impact location  2003   a  and middle impact location  2003   b  of playing surface  2003  can be located above sensor  2005 , and middle impact location  2003   c  and center impact location  2003   d  can be located above sensor  2007 . 
     In some embodiments sensor  2007  can be adjusted to a higher sensitivity level than sensor  2005 , and outer impact location  2003   a  can have a MIDI velocity range of 16-22, middle impact location  2003   b  can have a MIDI velocity range of 28-32, middle impact location  2003   c  can have a MIDI velocity range of 34-42, and center impact location  2003   d  can have a MIDI velocity range of 40-48. 
     In other embodiments, sensor  2007  can be adjusted to a lower sensitivity level than sensor  2005 , and outer impact location  2003   a  can have a MIDI velocity range of 42-50, middle impact location  2003   b  can have a MIDI velocity range of 36-42, middle impact location  2003   c  can have a MIDI velocity range of 28-32, and center impact location  2003   d  can have a MIDI velocity range of 16-22. 
     In other embodiments, sensor  2007  can be adjusted to a sensitivity level that is equal to the sensitivity level of sensor  2005 , and outer impact location  2003   a  can have a MIDI velocity range of 36-40, middle impact location  2003   b  can have a MIDI velocity range of 36-40, middle impact location  2003   c  can have a MIDI velocity range of 36-40, and center impact location  2003   d  can have a MIDI velocity range of 36-40. 
       FIG. 21  is a circular diagram illustrating an overhead view of a sensor inside an electronic percussion instrument, consistent with some embodiments of the present disclosure. Electronic percussion instrument  2101  may comprise structural body  2103 , dampening material  2105 , plate  2107 , and shock absorbing posts  2109 . 
     In some embodiments structural body  2103 , dampening material  2105 , plate  2107 , and shock absorbing posts  2109  can be composed of the same material as structural body  713 , dampening material  711 , plate  707 , and shock absorbing posts  705 . In some embodiments structural body  2103 , dampening material  2105 , plate  2107 , and shock absorbing posts  2109  can be arranged the same way that structural body  713 , dampening material  711 , plate  707 , and shock absorbing posts  705  can be arranged in electronic percussion instrument  701 . 
       FIG. 22  shows a circular diagram illustrating an overhead view of two sensors inside an electronic percussion instrument, consistent with some embodiments of the present disclosure. 
     Electronic percussion instrument  2201  may comprise structural body  2203 , dampening material  2205 , plate  2207 , plate  2209 , and shock absorbing posts  2211 . 
     Structural body  2203  can enclose dampening material  2205 . 
     Dampening material  2205  can enclose plate  2207 . 
       FIG. 23  is an exemplary image of a sensor inside an electronic percussion instrument, consistent with some embodiments of the present disclosure. 
     Sensor enclosure  2305  can comprise sensor  2309 , dampening material  2311 , and plate  2313 . Sensor  2309 , dampening material  2311 , and plate  2313  can be composed of the same materials as sensor  601 , dampening material  711 , and plate  707  respectively. Sensor  2309 , dampening material  2311 , and plate  2313  can be arranged the same way sensor  309 , dampening material  311 , and plate  313  can be arranged within sensor enclosure  305 . 
     Sensor  2309  can have a circular shape. In some embodiments sensor  2309  can have a triangular, quadrilateral, or ring shape. 
       FIG. 24  is an exemplary image of two sensors inside an electronic percussion instrument, consistent with some embodiments of the present disclosure. 
     Electronic percussion instrument  2401  may comprise one or more flanges  2403  extending from sensor enclosure  2405  to the perimeter of the interior of shell  2407 . 
     Sensor enclosure  2405  can comprise sensor  2409 , dampening material  2411 , and plate  2413 . Sensor  2409 , dampening material  2411 , and plate  2413  can be composed of the same materials as sensor  601 , dampening material  711 , and plate  707  respectively. Sensor  2409 , dampening material  2411 , and plate  2413  can be arranged the same way sensor  309 , dampening material  311 , and plate  313  can be arranged within sensor enclosure  305 . 
     Sensor  2409  can have a circular shape. In some embodiments sensor  2409  can have a triangular, quadrilateral, or square shape. 
     Sensor  2419  can have a ring shape. In some embodiments sensor  2419  can have a triangular, quadrilateral, or square shape. 
     In the preceding specification, the embodiments have been described with reference to specific exemplary embodiments. The specification and drawings are accordingly to be regarded as illustrative rather than restrictive sense. Other embodiments of the present disclosure may be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein.