Abstract:
A facility for the purpose of entertainment, education, or monitoring wherein there is provided an acoustic sensor ( 24 ) mounted on the outside of a toilet bowl ( 30 ) and a simple, inexpensive target ( 22 ) mounted to the inside of the toilet ( 28 ) thereby keeping the sensitive acoustic sensor and other electronics in a dryer and cleaner location. The sound of a urine stream contacting the target ( 22 ) propagates through the toilet ( 26 ) and is detected by the acoustic sensor ( 24 ). An analysis and feedback unit ( 32 ) monitors the sound of the urine stream contacting the target ( 22 ) and provides a message to the user indicating their success in hitting the target ( 22 ) with the urine stream.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   Not Applicable 
   FEDERALLY SPONSORED RESEARCH 
   Not Applicable 
   SEQUENCE LISTING OR PROGRAM 
   Not Applicable 
   BACKGROUND OF THE INVENTION 
   1. Field of Invention 
   This invention relates to a method of sensing a stream of urine or liquid upon a toilet, urinal surface or other liquid impacted surface and providing feedback relating to the accuracy, duration and intensity of the liquid stream for the purpose of monitoring, analysis, or entertainment. 
   2. Prior Art 
   Previously, prior art in this field included numerous inventions that allow a user to aim a stream of urine at a target in a toilet and register a score. U.S. Pat. No. 6,779,206 (2004) proposes a sensor in the toilet bowl or a sensor requiring installation of a protective shield in the toilet bowl. Complex electronics within the bowl are problematic because they are heavy and require a strong adhesive to affix to the bowl. Additionally, electronics in the bowl need robust and watertight housings that are expensive to replace when they fail due to exposure over time. Furthermore, the electronics will require a battery which, when out of energy, will involve an unhygienic removal and replacement operation considering its placement in a dirty toilet bowl. 
   Alternately, simple targets can be within the bowl but require a cumbersome wire or a set of wires leading into the bowl for signal transmission and power supply purposes. U.S. Pat. No. 6,772,454 (2004) shows an embodiment with a set of electronic devices in the toilet and a wire leading to a controller display outside the toilet. Such an embodiment would lead to the difficult-to-clean wire and the previously mentioned need for robust housing to protect sensitive electronics. 
   U.S. Pat. No. 6,098,211 (2000) uses audio analysis to detect the sound of the flushing toilet and trigger cleaning. It stops short of integrating such technology into a urine sensing entertainment system. 
   U.S. Pat. No. 6,723,929 (2004) uses audio analysis to determine when the toilet should flush and how much water should be used to flush it. It also stops short of integrating such technology into a urine sensing entertainment system. 
   BACKGROUND OF INVENTION—OBJECTS AND ADVANTAGES 
   Accordingly, several objects and advantages of our invention are derived by placing the urine sensor outside the bowl. Within the bowl is a simple and light target, constructed so that, when impacted by urine, it creates a different sound than the sound of urine impact on the inner toilet wall surface. There are no complex electronics within the toilet bowl, and only a microphone need be mounted on the outer surface of the toilet bowl to capture the sound of urine impact. Both the target and the sensor will be light enough to adhere to the toilet surface with minimal adhesive. No power supply will be required in the toilet bowl or outside of the bowl. Also, there will be no need for drilling or cutting of the toilet surface to install the system. This system can be installed on urinals or toilets with the target located on the area where the urine impacts and the sensor located on the outer side of the urinal or toilet. 
   Cleaning of the target and sensor can be carried out with the thoroughness normally afforded to the bowl of the toilet. Strong adhesives will hold the lightweight target and sensor to the toilet despite vigorous cleaning. Should, over time, either sensor housing or target fall off, replacement sensor housings and targets and can be replaced for a small fraction of the cost of the entire urine detection entertainment system. 
   Electronics to analyze the urine stream and provide feedback can be mounted in a location that is remote from the sensor. The preferred location for these electronics is in view of the user. The most likely locations are on top of the toilet tank or mounted to the wall behind the toilet. In these locations, there will be minimal need for cleaning and minimum exposure to moisture. 
   Audio analysis can be used to implement a game and not just cleaning or flushing, as proposed in earlier art. 
   SUMMARY 
   A urine sensor consisting of an acoustic sensor mounted on the exterior of a toilet and a target mounted on the interior wall of the toilet bowl. An electronic system senses the output of the acoustic sensor to determine if the urine stream is impacting the target or other areas of the toilet bowl. A display will provide positive feedback to the user if the target is impacted by urine. 

   
     DRAWINGS—FIGURES 
     FIG.  1 —Perspective view of the preferred embodiment 
     FIG.  2 —Sectional view of the sensor assembly in the preferred embodiment 
     FIG.  3 —Front view of the target in the preferred embodiment 
     FIG.  4 —Block diagram of the circuit for the analysis and feedback unit in the preferred embodiment 
     FIG.  5 —Flowchart of the system operation in the preferred embodiment 
     FIG.  6 —Perspective view of an alternative embodiment of the system on a urinal without a proximity sensor 
     FIG.  7 —Block diagram of the circuit for the analysis and feedback unit in an alternative embodiment of the system on a urinal without a proximity sensor 
     FIG.  8 —Perspective view of an alternative embodiment of the system on a urinal with an existing proximity sensor 
     FIG.  9 —Block diagram of the circuit for the analysis and feedback unit in an alternative embodiment of the system on a urinal with an existing proximity sensor 
     FIG.  10 —Perspective view of an alternative embodiment of the system with a supplemental solar power supply 
     FIG.  11 —Block diagram of the circuit for the analysis and feedback unit in an alternative embodiment of the system with a supplemental solar power supply 
     FIG.  12 —Perspective view of an alternative embodiment of the system with a multiplicity of targets, an interactive display and an expansion slot 
     FIG.  13 —Perspective view of an alternative embodiment with a wireless communication system 
     FIG.  14 —Block diagram of the circuit for the sensor and analysis unit in an alternative embodiment with a wireless communication system 
     FIG.  15 —Block diagram of the circuit for the feedback unit in an alternative embodiment with a wireless communication system 
   

   DRAWINGS—REFERENCE NUMERALS 
   
       
         20 —the system 
         22 —the target 
         24 —the sensor 
         25 —the urinal 
         26 —the toilet 
         27 —toilet bowl 
         28 —the toilet bowl interior wall 
         29 —toilet water surface 
         30 —the toilet bowl exterior wall 
         31 —the urinal interior wall 
         32 —analysis and feedback unit for residential toilet 
         33 —analysis and feedback unit button for residential toilet 
         34 —analysis and feedback unit display 
         35 —sensor and analysis unit with wireless circuitry 
         36 —feedback unit with wireless circuitry 
         37 —analysis and feedback unit for commercial urinal with sting proximity detector 
         38 —expansion slot 
         39 —removable memory 
         40 —analysis and feedback unit with solar panel for residential toilet 
         41 —solar panel 
         42 —analysis and feedback unit with proximity detector for commercial urinal 
         43 —the urinal exterior wall 
         44 —the multiple target display 
         45 —the second smaller target 
         46 —the third square target 
         47 —the urinal with existing proximity sensor 
         48 —analysis and feedback unit with multiple target display and expansion slot 
         50 —acoustic sensor 
         52 —foam acoustic sensor housing 
         54 —upper interior of foam acoustic sensor housing 
         56 —dual conductor wire 
         58 —conduit 
         60 —outer rim of foam housing with adhesive 
         80 —dome 
         83 —tabs with adhesive on one side 
         90 —proximity sensor 
         91 —existing proximity sensor 
       A—signal from acoustic sensor to amplification stage 
       B—signal from button to processor 
       C—signal from analog to digital converter to processor 
       D—signal from processor to display driver 
       M—signal from proximity sensor to processor 
       O—signal from amplification circuit to processor 
     
  
   DETAILED DESCRIPTION 
   The above described drawings illustrate preferred and alternative embodiments of the invention, a toilet entertainment device  20  that is comprised of a target  22  and a sensor  24  connected by a wire  56  to an analysis and feedback unit  32 . The toilet entertainment device  20  is mounted on a toilet  26 . The invention will feedback the properties of the stream of urine via a score based on pressure, duration and accuracy of the urine stream. 
   DESCRIPTION—FIGS.  1 – 5 —PREFERRED EMBODIMENTS 
   The preferred embodiment of a toilet entertainment device  20  is illustrated in  FIG. 1  (perspective view) and  FIG. 4  (system block diagram). A simple semi-permanent, disposable target  22  is mounted in a toilet  26  on toilet bowl interior wall  28  above toilet water surface  29 . A sensor  24  is mounted on toilet exterior wall  30 . Sensor  24  includes an acoustic sensor or microphone  50  with the diaphragm of acoustic sensor  50  facing toilet exterior wall  30 . When a user directs a stream of urine at target  22 , the unique sound of the urine stream upon target  22  is detected by acoustic sensor  50  and processed by an analysis and feedback unit  32 . This acoustic method of urine stream analysis allows simple, clean installation of the target without wires in toilet bowl  27 , wires along toilet bowl interior wall  28  or modifications such as drilling to toilet bowl  27 . Cleaning is simplified when electronics are not directly exposed to toilet bowl interior wall  28 , where the most vigorous cleaning occurs. 
   A signal A ( FIG. 4 ) from acoustic sensor  50  propagates through a dual conductor wire  56  into an analysis and feedback unit  32 . Analysis and feedback unit  32  determines via audio analysis of signal A if the user is accurately hitting target  22  with a stream of urine. Analysis and feedback unit  32  includes a display  34  which will feedback a score to the user. Analysis and feedback unit  32  increases the score for higher urine stream pressure and longer urine stream duration as long as the urine stream accurately hits target  22 . 
     FIG. 3  illustrates the preferred embodiment of target  22 . In the preferred embodiment, target  22  is a dome  80  formed from an inexpensive plastic. In the preferred embodiment, the manufacturing process used to produce halves of ping-pong balls would be adapted to produce dome  80  with a multiplicity of flexible plastic tabs  83  on the edge of dome  80 . 
   In the preferred embodiment shown in  FIG. 3  there is an adhesive coating on plastic tabs  83 . In the preferred embodiment the adhesive coating is that used for surfboard deckgrip. In other embodiments, the adhesive coating is chosen by one skilled in the art to readily adhere to the clean, dry interior toilet surface  28  and to maintain adhesion between plastic tabs  83  and toilet interior wall  28  in the presence of impacts from solids or liquids on and around target  22 . The adhesive coating is protected by a peel-away cover. After removal of the peel-away cover, the adhesive surface is exposed and can be easily attached to the clean, dry interior toilet surface  28 . 
   In the preferred embodiment target  22  may have a printed, embossed or etched logo or picture visible to the user to serve as further encouragement to the user to aim their urine stream at target  22 . After the picture on target  22  has worn off, the adhesion of target  22  to interior toilet wall  28  is beginning to fail, or the user has deemed target  22  an otherwise unworthy recipient of his or her stream of urine, it may be pried off with a flat edged metal tool such as a screwdriver and flushed down toilet  26  or thrown away. A new target  22  can be selected by the user to replace the removed target. 
   Alternative embodiments of the shape of the target include a flat sticker, a recess in interior toilet wall  28  or a shape designed by one skilled in the art such that the stream of urine will not deflect outside of bowl  27  upon striking target  22 . Other alternative embodiments of target  22  use foam, rubber or any other material which, when contacted with a urine stream, has a characteristic spectral range or sonic signature in which sound frequencies with maximum energy lie that is different from the sonic signature of urine contacting toilet interior wall  28 . In other alternative embodiments, target  22  may be affixed to interior toilet wall  28  with hook-and-loop fasteners, suction cups or mechanical structures placed in bowl  27  which stabilize target  22 . 
     FIG. 2  illustrates the preferred embodiment of sensor  24 . Acoustic sensor  50  is used in sensor  24 . Acoustic sensor  50  is contained within a foam housing  52 . The acoustic sensor  50  also has dual conductor wire  56  leading from acoustic sensor  50  to analysis and feedback unit  32 . Foam housing  52  contains a conduit  58  for dual conductor wire  56 . The outer rim of foam housing  60  has an adhesive coating. The adhesive coating on the outer rim of the foam housing  60  adheres to toilet bowl exterior wall  30 . The adhesive coating has a protective peel-away cover. Upon removal of the peel-away cover, the adhesive surface is exposed and can be easily attached to the clean, dry toilet bowl exterior wall  30 . The adhesive coating is selected by one skilled in the art so as to maintain a lasting adhesion between foam housing  52  and toilet exterior wall  30  so as not to be affected by cleaning or impacts from solids or liquids on and around sensor  24 . In one embodiment the adhesive coating is that used for surfboard deckgrip. The properties of the adhesive coating are such that, when installed on a clean dry surface they withstand moisture and physical contact. 
   In the preferred embodiment acoustic sensor  50  is sandwiched between upper interior of the foam housing  54  and toilet bowl exterior wall  30 . The close proximity of acoustic sensor  50  to toilet bowl exterior wall  30  allows for the sound transferred through toilet  26  to reach acoustic sensor  50  with minimal dissipation. Foam housing  52  combined with the close proximity of acoustic sensor  50  to toilet exterior wall  30  helps keep noise such as yelling or footsteps from influencing signal A. 
   In  FIG. 1  toilet entertainment device  20  has analysis and feedback unit  32 . The wire  56  transmits signal A from sensor  24  to analysis and feedback unit  32 . Feedback is generated in the form of audio and/or visual feedback generated by analysis and feedback unit  32 . 
   The block diagram in  FIG. 4  represents analysis and feedback unit  32 . Dual conductor wire  56  carries signal A from acoustic sensor  50  into analysis and feedback unit  32 . Signal A is the input into an operational amplifier or amplification stage inside analysis and feedback unit  32 . The electrical values of the circuitry in the amplification stage and the components required for biasing the amplification stage are determined by one skilled in the art. The amplification stage output signal O feeds into the analog input of an analog to digital or a/d converter. The digital output signal C of the a/d converter enters a digital signal processor or DSP. A user accessible button or switch  33  mounted on the exterior of the analysis and feedback unit  32  feeds a signal B into the DSP. The DSP outputs a signal D. The signal D feeds into a display driver. The display driver controls a liquid crystal display or LCD. The LCD or display  34  is mounted on the exterior of analysis and feedback unit  32 . Display  34  is for user feedback. The output indicates a positive result when target  22  is contacted with a stream of urine. The result is unchanged or negative when the stream of urine contacts the water or a part of toilet  26  where target  22  is not located. 
   In alternative embodiments (not shown) the output from the DSP is displayed visually, audibly, or with any other device necessary to indicate the level of success achieved by the user in connecting their stream of urine to target  22 . 
   In the preferred embodiment of  FIG. 4  electrical power for all components in analysis and feedback unit  32  is provided by four AA batteries. 
   DESCRIPTION—FIGS.  6 – 15 —ALTERNATIVE EMBODIMENTS 
   An alternative embodiment in  FIG. 10  employs a solar panel  41  mounted to the exterior of an analysis and feedback unit  40 . Solar panel  41  provides power to allow analysis and feedback unit  40  to constantly monitor acoustic sensor  24  for a new user after toilet  26  has been flushed. The use of solar power extends battery life.  FIG. 11  shows the block diagram of analysis and feedback unit  40 . The solar panel, batteries, and other functional blocks interact with a power management system, designed by one skilled in art, to ensure solar power is efficiently distributed to batteries for charging and to other functional blocks for routine system operation. An alternative embodiment (not shown) designed by one skilled in the art employs existing residential or commercial power sources or a power supply already existing on a toilet or urinal. 
   In an alternative embodiment mounted on a urinal  25  in  FIG. 6 , an analysis and feedback unit  42  includes a motion or proximity sensor module  90  to detect the presence of a user in front of analysis and feedback unit  42 . The purpose of proximity sensor  90  is to allow the DSP ( FIG. 7 ) to reset the score and initiate a new game upon detection of a new user. In this embodiment ( FIG. 6 ) dual conductor wire  56  runs, hidden from view, behind the water pipes and valves of urinal  25  to connect analysis and feedback unit  42  and sensor  24 . Sensor  24  is mounted on the side or back of urinal exterior wall  43  and target  22  is mounted on the urinal interior wall  31 . In the block diagram  FIG. 7  of this alternative embodiment, proximity sensor module  90  interfaces directly with the DSP. The sensor can be designed by one skilled in the art to detect the user when the user approaches or departs the area around the toilet. In an alternative embodiment (not shown) analysis and feedback unit  42  contains a sensor that detects a user entering the toilet area when the user switches on the lights. 
   An alternative embodiment in  FIG. 8  shows a urinal  47  with a motion or proximity sensor  91  used in a system to flush urinal  47  when the user departs. Installed directly above or below proximity sensor  91  is an analysis and feedback unit  37 . In  FIG. 9  the block diagram of analysis and feedback unit  37  includes an input for the proximity sensor&#39;s signal M. This signal M is used in proximity sensor  91  to trigger flushing of urinal  47  when the user departs. One skilled in the art can use signal M from proximity sensor  91  as an input to analysis and feedback unit  37 . The signal M will be used by the DSP in analysis and feedback unit  37  to detect a new user and initialize the system for a new game sequence. 
   An alternative embodiment  FIG. 13  is envisioned that would utilize wireless technology to transmit digital data from a sensor  35  to a feedback unit  36 . The block diagram in  FIG. 14  shows an amplification stage, analog to digital conversion, processing, and wireless hardware in the housing of the sensor  35 . A block diagram in  FIG. 15  indicates additional processing and wireless hardware in the feedback unit  36 . The wireless technology would remove the need for a wire to carry an electrical signal from the sensor to the feedback method. In alternative embodiments all analysis hardware is contained in feedback unit  36 . 
   An alternative embodiment in  FIG. 12  has multiple targets, each producing a different sound when struck by a stream of urine. This embodiment is shown with a target  22 , a smaller target  45  and a square target  46 . A multiple target display  44  provides a feedback that encourages the user to aim the urine stream at a specific target. 
   In  FIG. 12  an expansion slot  38  in the analysis and feedback unit  48  contains a portable media device  39  such as a flash memory card or other removable memory containing data to change the entertainment program, education program, game program or personalize the analysis or feedback parameters for a given user or plurality of users. For example, in  FIG. 12  analysis and feedback unit  48  is initially loaded with a game in which the user shoots ducks by aiming a urine stream at the correct target as directed by display  44 . In this embodiment, the user has the option of inserting removable memory  39  into expansion slot  38 . In this embodiment, removable memory  39  allows the user to play a different game, with, for example, a space ship that dodges asteroids by jumping to areas corresponding to the target contacted by the urine stream. In another removable memory, the user may store personal preferences regarding analysis and feedback parameters such as background color used on the display or the sensitivity of the algorithm detecting the loudness of a urine stream upon the target. 
   An alternative embodiment (not shown) is envisioned in a facility with multiple urinals or toilets with the invention located at each toilet or urinal. In this embodiment the analysis and feedback units for each toilet or urinal would be linked with a communications system so in the case of multiple users, the display would feedback the status and score of each user on all displays in order to stimulate competition among users. 
   OPERATION—FIGS.  1 , 4 , 5 —PREFERRED EMBODIMENTS 
   In the preferred embodiment ( FIG. 1 ) the user&#39;s urine stream impacts the interior toilet wall  28 , the surface of target  22  or the surface of the toilet water  29 . A different sound is generated when a liquid or urine stream contacts each of these surfaces. Sensor  24 , containing acoustic sensor  50 , detects the sound generated by urine striking the various surfaces, background noise in the vicinity of the toilet and sounds associated with the flushing of the toilet  26 . Dual conductor wire  56  connecting acoustic sensor  50  to analysis and feedback unit  32  carries the electrical signal A ( FIG. 4 ) representing the sound into the amplification stage. One skilled in the art can bias the amplification stage to generate an output signal O appropriate for input into the a/d converter. The digital output signal C generated by the a/d converter enters the Digital Signal Processor or DSP. 
   The signal C is a digital representation of the sound sensed by acoustic sensor  50 . The DSP is programmed by one skilled in the art to sample signal C and compare it to reference sounds collected during calibration. The DSP program algorithm only reacts to pre-calibrated sounds. The DSP program ignores background noise and other sounds that don&#39;t match those collected during calibration. Background noises such as footsteps, lifting of the toilet seat, talking or yelling may share some frequency components with pre-calibrated sounds, but will not share all frequencies or contain the same pattern of average frequencies over time. This comparison will prevent unwanted noises from affecting the feedback displayed to the user. 
   In the preferred embodiment, the DSP generates an output signal D that feeds into a display driver. The display driver creates and changes images on the display  34 . The display  34  shows a numerical score during regular operation. The score increases quickly with a strong and loud stream of urine upon target  22 . The score increases at a slower rate with a weak and quieter stream of urine upon target  22 . The score will be saved and, if within the top  10  scores, will be included in a leaders&#39; list. 
   OPERATION OF DSP PROGRAM FLOW—FIG.  5 —PREFERRED EMBODIMENT 
   The audio analysis program represented by the flowchart in  FIG. 5  is the DSP program flow used to analyze the input signal, determine the level of performance and display an output to the user. The flow is divided into a calibration flow and a game flow. 
   When the unit is first installed on toilet  26  and power is applied to analysis and feedback unit  32  the DSP will poll a nonvolatile memory bit named calibration_complete. The calibration_complete bit indicates if analysis and feedback unit  32  has completed a full calibration. If analysis and feedback unit  32  has not previously been calibrated, the DSP will enter a user interactive calibration mode. 
   The calibration mode will begin by prompting the user to depress button  33  on analysis and feedback unit  32  when the user is ready to aim a water stream at target  22 . The characteristics of the water stream are chosen to duplicate the characteristics of a user&#39;s stream of urine. The preferred embodiment of the method for duplicating a urine stream is a six ounce water bottle with a nozzle size and shape chosen by one skilled in the art to emulate a stream of urine when water passes through it. After depressing button  33 , the user will shoot the water stream at target  22 . In the preferred embodiment the DSP is programmed by one skilled in the art to use a Fast Fourier Transform or FFT optimized to detect a pattern in the audio frequencies with maximum energy or sonic signature of the sound created when the water stream contacts target  22 . Assuming an audio frequency range of 50–10000 Hz, sampling would need to occur at a rate of 20000 Hz to prevent aliasing. To implement the FFT with a resolution of 50 Hz, a 512-point FFT can be used. Upon completion of the FFT, the frequency components are saved to a nonvolatile memory location on the DSP or connected to the DSP. 
   Next, the calibration mode will prompt the user to depress button  33  on analysis and feedback unit  32  when ready to aim a water stream at the toilet&#39;s interior wall  28 . At this point, the DSP uses an FFT optimized to detect the sonic signature of the sound created when the water stream contacts the toilet&#39;s interior wall  28 . The frequency components are saved to a nonvolatile memory location. 
   Next, the calibration mode will prompt the user to depress button  33  when ready to aim a water stream at the toilet bowl water surface  29 . Again, the DSP uses the FFT algorithm to detect the sonic signature of the sound created when the water stream contacts the toilet bowl water surface  29 . The frequency components are saved to a nonvolatile memory location. 
   Finally, the calibration mode will prompt the user to depress button  33  when ready to flush toilet  26 . The DSP detects the sonic signature-created with the sound of flushing water. The frequency components are saved to a nonvolatile memory location. With the frequency sampling complete the calibration_complete bit is set and the DSP enters Game Mode. Upon the next power up or reset the DSP will poll the calibration_complete bit, determine the calibration is finished and enter the Game Mode. Should the user wish to recalibrate the toilet entertainment system  20 , possibly because of relocation of the system  20  or replacement of the target  22 , the DSP will reenter calibration mode, via an interrupt, when the user depresses button  33  for three seconds. 
   The first step in game mode is detection of the user. In the preferred embodiment in  FIG. 1 , analysis and feedback unit  32  is actively monitoring acoustic sensor  50  at all times. In the flowchart in  FIG. 5 , when a user begins urinating into toilet bowl  27 , analysis and feedback unit  32  will detect the user by sensing the sound of the impact of the urine stream upon target  22 , the toilet bowl interior wall  28 , or the toilet bowl water surface  29 . In alternative embodiments the user will depress button  33  to signal their presence. The DSP is programmed to clear the score to zero after detection of the user. 
   Next, the DSP is programmed by one skilled in the art to use the FFT algorithm to detect a pattern in the sonic signature of urine striking target  22 . The DSP will increase the score if it matches the primary frequency components of signal C to those saved in nonvolatile memory during calibration of target  22 . The DSP will leave the score unchanged if it matches the primary frequency components of signal C to those saved in nonvolatile memory during calibration of the toilet bowl interior wall  28 , the toilet bowl water surface  29  or background noise. The DSP will be programmed by one skilled in the art to update the score to display  33  or in alternative embodiments, to any other feedback device. After updating the score, the DSP will allow 0.25 seconds to elapse before sampling sensor  24  again. 
   The DSP will stop the current game session if the sound of the flushing toilet  26  is detected by sensor  24 . Additionally, if, for 10 seconds, the DSP does not detect the sonic signatures created by the sound of urine striking the target  22 , the toilet bowl interior wall  28 , or the toilet bowl water surface  29 , the DSP will stop the current game session. After a game session has stopped the DSP will continue to output the score on the display  33  for the next user to view. This will offer the next user a competitive score to match or exceed. Alternately, the DSP may alternate between the last score and a listing of the top  10  scores leaders. 
   OPERATION—FIGS.  6 , 8 , 10 , 12 , 13 —ALTERNATIVE EMBODIMENTS 
   Alternative embodiments in  FIG. 6  and  FIG. 8  are envisioned that utilize a motion sensor connected to the analysis and feedback unit. The motion sensor is designed by one skilled in the art to detect the user&#39;s presence in front of urinal  25  or urinal  47 . This embodiment would preserve battery power and allow analysis and feedback unit  37  in  FIG. 8  and analysis and feedback unit  42  in  FIG. 6  to operate longer on a given set of batteries. 
   An alternative embodiment  FIG. 10  is envisioned utilizing solar panel  41  mounted on analysis and feedback unit  40 . This embodiment would allow the DSP to constantly monitor the sensor for sound without drawing as much battery power and allow analysis and feedback unit  40  to operate longer on a given set of batteries. This embodiment would require analysis and feedback unit  40  to be placed under a window or skylight to allow sun to shine on the solar panel. 
   An alternative embodiment in  FIG. 12  uses a multiplicity of targets  22 ,  45 , and  46 . Each target, owing to its different shape, size, or material composition, produces a different sound when struck by a stream of urine. During calibration, each target must be calibrated separately. In this alternative embodiment, the user will attempt to aim the urine stream at the specific target  22 ,  45 , or  46  as directed by analysis and feedback unit  48 . After correctly contacting the target, analysis and feedback unit  48  will increase the score and change the image to direct the user to a different target. In alternative embodiments, a moving image will appear on a display  44 . The image will move into different sections of display  44 . Each section is represented by target  22 ,  45 , or  46 . The user will attempt to hit the moving image by aiming the urine stream at the target corresponding to section containing the moving image. The score will be increased each time the user hits the correct target. 
   In  FIG. 12  an expansion slot  38  is provided in analysis and feedback unit  48 . When the user inserts a removable memory  39  into expansion slot  38  the DSP will interact with a system designed to read data from removable memory  39 . When the DSP processes removable memory  39  data, it will change parameters or games according to the data on removable memory  39 . Removable memory  39  may contain data that changes the type of game available to the user, the user&#39;s personal settings for display parameters such as background color or high scores or the user&#39;s personal settings for analysis parameters such as acoustic sensitivity. In the case of acoustic sensitivity, the user may wish to change the sensitivity of the algorithm detecting the sonic signature to compensate for an unusually strong or weak urine stream. Upon removal of removable memory  39  from expansion slot  38  analysis and feedback unit  48  will return to its state before the insertion of removable memory  39 . 
   It is envisioned that features from one embodiment could be added to another embodiment. For instance, the wireless system embodied in  FIG. 13  could be adapted for use in the urinal and proximity sensor embodiment in  FIG. 6 . One skilled in the art could envision other embodiments not detailed in the specification. The scope of the invention is to be interpreted only in conjunction with the appended claims. 
   CONCLUSIONS, RAMIFICATIONS AND SCOPE 
   This method of sensing a urine stream using an acoustic sensor mounted on the exterior of a toilet bowl is fun to use for the purposes of entertainment and toilet training education. It is easily installed on any toilet or urinal with minimal changes to cleaning routines after installation. Furthermore, it is envisioned the invention could be easily adapted to the carnival water gun accuracy game, a fun system to use when milking a cow, or any other use involving liquid flow onto a surface. It will scale for industrial uses involving monitoring the transfer of liquid or other flowing materials. 
   The target can be customized by the user using a waterproof pen. The user would be able to place logos, pictures or words that encourage or discourage aiming a stream of urine at the target. Furthermore, a sheet of material could be inserted in a computer printer and, with the proper software the user would create targets on a PC for placement in the toilet or urinal. 
   Although the specification above contains multiple specificities, these should not be construed as limiting the scope of the invention, but as merely providing illustrations of some of the presently preferred embodiments of the invention. The scope of the invention should be determined by the appended claims and their legal equivalents, rather than examples given.