Abstract:
A noise level indicator in the form of a traffic light having respective red, yellow, and green lights. The noise level indicator receives ambient noise through a built-in microphone and compares the ambient noise level against a predetermined acceptable decibel level. The noise level indicator shows whether the ambient noise level is below, at, or above the predetermined acceptable decibel level by respectively illuminating the green, yellow, or red light. The red light can be accompanied by an audible siren, and the yellow light flashes to call attention to borderline and unacceptable ambient noise levels.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of Invention  
           [0002]    The present invention relates to sound and noise level indicators, and more specifically to noise level indicators which visually indicate the noise level using lights.  
           [0003]    2. Description of Related Art  
         Monitoring of Noise levels  
         [0004]    The monitoring of noise levels is of prime importance such as for speakers in auditoriums so everyone present can comfortably hear the speaker, and at rock concerts so the band can be heard at a satisfactorily loud volume level which does not damage the hearing of those in attendance. Likewise. undesirable sounds, or ambient noise, is desirable to be monitored in classrooms, and back stage at theater so as not to reach a level which is disturbing to others.  
         Noise level Indicators  
         [0005]    A noise level monitoring and indicating system is disclosed in U.S. Pat. No. 4,424,511 issued to Alberts, Jr. The system designed for use in classrooms, buses, and other such relatively large areas in which the noise level is to be monitored. A plurality of individual microphones are distributed about in the area to be monitored. The microphones are each connected to a box having a plurality of voice operated relays, one for each microphone. When a voice operated relay sends a noise level above its operating threshold, it increments a counter and activates a relay which controls an external reinforcement device comprising a green, a yellow, and a red light signifying that the predetermined maximum noise level has been exceeded. The audio signal detected by each voice activated relay is coupled to an additional voice operated relay which includes a connector and a relay output device similar to those in the individual channels. This additional voice operated relay functions as a summing device for ambient noise levels sensed throughout the area monitored by all of the microphones. Each voice operated relay also provides an output via a sensor selector switch and audio amplifier to a decibel meter, a monitor speaker, and optional remote monitors.  
           [0006]    A noise level indicator specifically designed for use in a classroom is disclosed in U.S. Pat. No. 3,480,912 issued to Speeth et al. The device includes a plurality of lights which are sequentially illuminated in accordance with the noise level detected by an attached microphone. The system is used to provide feedback to students as to whether they are speaking too softly, at the right sound level, or too loudly.  
           [0007]    Gibbs in U.S. Pat. No. 3,440,349 and Gibbs et al. in U.S. Pat. No. 3,797,012 provide ambient noise level indicator systems wherein a microphone detects the ambient noise level and an electronic noise circuit controls a plurality of lamps in response to the volume of ambient noise detected by the microphone whereby an indication of an acceptable ambient noise level or unacceptable ambient noise level is provided.  
           [0008]    Ford et al. in U.S. Pat. No. 3,304,368 is another example of prior art systems where a means is provided to indicate when the ambient noise level within a school bus exceeds a predetermined value and Ott in U.S. Pat. No. 3,582,671 provides a visual indication when the ambient noise level in a study room or library exceeds a predetermined level.  
           [0009]    Many systems have been developed to determine ambient noise levels and to provide a qualitative indication of the instantaneous ambient noise levels. However, there is a need for an attractive device which catches the eye of persons present, which has an adjustable sensitivity level to indicate the particular decibel level of the noise desired by the individual user, which provides feedback in a fun and interesting way so people use it, which provides auxiliary attention-getting features besides visual indicators, and which has the flexibility to be placed on a table or hung on a wall to maximize visibility.  
         SUMMARY OF INVENTION  
       1. Advantages of the Invention  
         [0010]    One of the advantages of the present invention is that it provides an attractive, attention-getting design for a noise level indicator.  
           [0011]    A further advantage of the present invention is that it provides feedback in a fun and interesting way so people use it  
           [0012]    Another advantage of the present invention is it provides auxiliary attention-getting features including flashing light and sound.  
           [0013]    Another advantage of the present invention is it provides an adjustable sensitivity level to indicate the particular decibel level of the noise desired by the individual user as indicated by the lights and sounds.  
           [0014]    Another advantage of the present invention is the flexibility to be placed on a table or hung on a wall to maximize visibility.  
           [0015]    These and other advantages of the present invention may be realized by reference to the remaining portions of the specification, claims, and abstract.  
         2. Brief Description of the Invention  
         [0016]    The invention comprises a noise level indicator and a method of use of the noise level indicator to provide indication to persons present in the adjacent area of the ambient noise level,  
           [0017]    The noise level indicator includes a microphone adapted to pick up and convert ambient sound waves to an electrical signal. An audio amplifier is operatively connected to the microphone for receiving and amplifying the electrical signal. A logic network is operatively connected to said audio amplifier for receiving an output from the audio amplifier. The logic network is adapted to produce electrical output signals indicative of the ambient noise level input to the microphone. An indicator is operatively connected to the logic network which is adapted to convert the electrical output signals from the logic network to indications of the ambient noise level. The indications include when the ambient noise level is generally below a predetermined decibel level, is generally at the predetermined decibel level, and is generally above the predetermined decibel level. The indications are perceptible by the persons in the adjacent area to provide feedback to them when ambient noise levels are getting too high or actually too high.  
           [0018]    The noise level indicator is preferably includes an elongate, generally rectangular housing configured to generally resemble a traffic signal. The housing has a front side with three large holes disposed in a vertical line one above the other. The housing encloses the audio amplifier, the logic network, the indicator, and preferably the microphone. The indicator comprises three lights of different colors which are visible through respective of the three large holes. An uppermost light appears red when illuminated, a middle light appears yellow when illuminated, and a lowermost light appears green when illuminated. The logic network is adapted to cause the lowermost light to illuminate when the ambient noise level is generally below the predetermined decibel level, cause the middle light to illuminate when the ambient noise level is generally at the predetermined decibel level, and cause said uppermost light to illuminate when the ambient noise level is generally above the predetermined decibel level. A variable sensitivity selector is operatively connected the audio amplifier and the logic network to allow manual control of the output from the audio amplifier to the logic network so as to effectively control the predetermined decibel level at which the respective lights illuminate.  
           [0019]    The method of using the noise level indicator is for controlling the ambient noise level of persons present in a specified area. The method comprises two steps, the first of which is providing a noise level indicator in the form of a traffic light having respective red, yellow, and green illuminating lights responsive to the ambient noise level in the specified area. The second step comprises providing feedback concerning the ambient noise level to the persons present in the specified area using the noise level indicator by providing indications that the ambient noise level is acceptable by illuminating the green light, is marginal by illuminating the yellow light, and is excessive by illuminating the red light.  
           [0020]    The method preferably includes the yellow light illuminating by flashing, and the red light being accompanied by a siren to farther attract attention when ambient noise levels are getting too high or are too high.  
           [0021]    The above description sets forth, rather broadly, the more important features of the present invention so that the detailed description of the preferred embodiment that follows may be better understood and contributions of the present invention to the art may be better appreciated. There are, of course, additional features of the invention that will be described below and will form the subject matter of claims. In this respect, before explaining at least one preferred embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of the construction and to the arrangement of the components set forth in the following description or as illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]    Preferred embodiments of the present invention are shown in the accompanying drawings wherein:  
         [0023]    [0023]FIG. 1 is substantially a front quarter perspective view of a noise level indicator according to the invention;  
         [0024]    [0024]FIG. 2 is substantially an exploded view of the noise level indicator;  
         [0025]    [0025]FIG. 3 is substantially a schematic circuit diagram showing the circuit features of the noise level indicator; and  
         [0026]    [0026]FIG. 4 is substantially a schematic block diagram of the system of FIG. 3. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0027]    As shown in FIGS. 1 and 2, the present invention is a noise level indicator, generally indicated at  20 . Noise level indicator  20  comprises a housing  23 , respective red, yellow, and green light assemblies  26 ,  29 , and  32 , a microphone assembly  35 , a speaker assembly  38 , a rotary sensitivity selector switch  41  attached to a first circuit board  44 , and respective main power and sound on/off switches  47  and  50  attached to a second circuit board  53 .  
       Housing  
       [0028]    The housing  23  is in the form of a stoplight as used to control the flow of motor vehicle traffic on streets. Housing  23  includes a front half shell  56  and a mating rear half shell  59  which connect together using a plurality of screws  62  which extend through respective holes  65  in front half shell  59  and threadably engage respective threaded holes  68  of respective mounting posts  71  of rear half shell  59 . Front half shell  56  includes respective light holes  74 ,  77 , and  80 , covered from above by respective sun shades  83 ,  86 , and  89 . A selector switch hole  90 , a pair of switch holes  92  and  95 , a microphone hole  98 , and a speaker hole  101  extend through front half shell  56  below light opening  80 . Rear half shell  59  includes a pair of separation baffles  104  and  107  which split housing  23  into three separate light chambers  110 ,  113 , and  116 . Housing  23  includes a pair of cushion legs  119  which mount to respective tabs  122  and  125  of front half shell  56  and tabs  128  and  131  of rear half shell  59  for placement of noise level indicator  20  on a horizontal surface  134 . Alternatively, rear half shell  59  includes a pair of mounting key holes  137  and  140  in respective rearward projections  143  and  146  for wall mounting noise level indicator  20 .  
       Light Assemblies  
       [0029]    Red, yellow, and green light assemblies  26 ,  29 , and  32  include respective translucent red, yellow, and green filters  149 ,  152 , and  155  which connect to front half shell  56  covering the respective light holes  74 ,  77 , and  80  using a plurality of screws  158  which thread into mating threaded holes (not shown) in front half shell  56 . Light assemblies  26 ,  29 , and  32  each further include a reflector  161 , a light bulb socket  164 , and a light bulb  167 . Reflectors  161  and sockets  164  attach to rear half shell  59  within the respective light chambers  110 ,  113 , and  116  using a plurality of screws  170  which extend through reflectors  161  and sockets  164  into pairs of threaded posts  173 . Light bulbs  167  extend through the respective reflectors  161 , twist locking into the respective sockets  170 . The respective light bulbs  167  are arranged to illuminate the respective chamber  110 ,  113 , and  116  shining through the respective red, yellow, and green filter  149 ,  152 , and  155 .  
       Microphone Assembly  
       [0030]    The microphone assembly  35  includes a microphone  176  which fits into a funneled mounting bracket  179 . Microphone  176  provides an input signal to audio amplifier circuit  227 . Mounting bracket  179  connects to front half shell  56  directly behind microphone hole  98  using a plurality of screws  182  which extend through mounting bracket  179  and threadably engage front half shell  56 . A decorative screen  185  is disposed between mounting bracket  179  and front half shell  56 .  
       Speaker Assembly  
       [0031]    Speaker assembly  38  includes a speaker  188  which connects to front half shell  56  directly behind speaker hole  101  with a decorative screen  191  therebetween using a plurality of screws  194  which extend through speaker  188  and threadably engage front half shell  56 .  
       Rotary Selector Switch, Circuit Boards, On/Off Switches, and Power  
       [0032]    Circuit board  44  with attached rotary switch  41  attach to front half shell  56  using a plurality of screws  197 , being positioned such that a rotary knob  200  of rotary selector switch  41  extends through selector switch hole  90  of front half shell  56  for operation external of housing  23 .  
         [0033]    Circuit board  53  with attached on/off switches  47  and  50  attach to front half shell  56  using a plurality of screws  203 , being positioned such that respective push buttons  206  and  209  of on/off switches  47  and  50  extend through the respective switch holes  92  and  95  of front half shell  56  for operation external of housing  23 .  
         [0034]    The noise level indicator  20  is provided with a suitable power cord  212  so that it can be connected to a convenient A.C. outlet (not shown).  
       Circuitry  
       [0035]    Noise level indicator  20  includes circuitry as is generally indicated at  215  in FIGS. 3 and 4. Circuitry  215  includes a power supply  218  which connects to an alternating current (AC) 120 volt, 60 cycle electrical power source  221  such as a wall outlet. A full wave rectifier circuit  224  rectifies the AC electrical power into direct current (DC) which powers the other circuits. Microphone  176  provides an input signal to an audio amplifier circuit  227 , which signal is amplified as an output signal which is fed to a variable sensitivity selector circuit  230 . The output signal of variable sensitivity selector circuit  230  is fed to an amplifier network  233  and the output signals thereof are sent to a logic network  236 . The output signals of logic network  236  are sent to both of a lamp output network  239  and a speaker control circuit  242 . The output signal of lamp output network  242  is in the visual form of red, yellow, and green light assemblies  26 ,  29 , and  32  respectively being illuminated. The output signal of speaker control circuit  242  is fed to speaker  188  for providing an audio sound signal to persons.  
         [0036]    Power Supply Circuit: Power supply  218  can a separate device which plugs into noise level indicator  20  as shown, or can be built into housing  23  as an integral part of noise level indicator  20 . Power supply  218  as shown is of the off-the-shelf type which includes a pair of prongs (not shown) which connect to a wall socket  219  which supplies 120 volt, 60 cycle electrical power. A transformer (not shown) within power supply  218  converts the 120 volts to 12 volts, 60 cycle at a lower amperage. A pair of output wires  245  and  248  are connected from the transformer to an end plug  251  which removably connects to a mating socket  254  affixed within housing  23 .  
         [0037]    Rectifier Circuit: Full wave rectifier circuit  224  includes a full wave rectifier bridge  257 , having a plurality of diodes  260 ,  263 ,  266 , and  269 , rectifies the 12 volt, 60 cycle electrical power received at socket  254 , supplying positive voltage to an integrated circuit  260 , and being connected to ground  272 . A pair of capacitors  275  and  278  each connect to ground  272 . The positive voltage is applied through the main power on/off switch  47  to a positive voltage feed  280  which powers the other circuits, which are connected to ground  272 .  
         [0038]    Audio Amplifier Circuit: Audio amplifier circuit  227  receives input from microphone  176  which is connected to the positive voltage feed  280  through a series of resistors  281 ,  284 , and  287 , and which is also connected to ground  272 . Respective capacitors  290 ,  293 , and  296  connect to the positive voltage ground  272  between resistors  281 ,  284 , and  287 . A transistor  299  is used to amplify the signal from microphone  176 , the base thereof receiving input through a variable resistor  302  connected to microphone  176  through a capacitor  305  and through a resistor  308  to ground  272  and through a capacitor  311 ,and resistor  281  and a pair of resistors  314  and  317 . The emitter of transistor  299  is connected through a resistor  321  to ground  272  and the collector thereof is connected to resistors  314  and  317 , and through a capacitor  324  and resistor  327  to the variable sensitivity selector circuit  230 .  
         [0039]    Variable Sensitivity Selector Circuit: Variable sensitivity selector circuit  230  includes a plurality of resistors  330 ,  333 ,  336 ,  339 ,  342 ,  345 , and  348  which are connected in series between resistor  327  of audio amplifier circuit  227  and ground  272 . Connections are made between the respective resistors  330 ,  333 ,  336 ,  339 ,  342 ,  345 , and  348  to rotary selector switch  41 , which is a seven step rotary type switch. The output of rotary selector switch  41  connects to amplifier network  233  through a capacitor  351  and resistor  354 . Therefore, a variable resistance can be applied between transistor  299  and amplifier network  233  to vary the sensitivity to ambient noise input to microphone  176 .  
         [0040]    Amplifier Network: Amplifier network  233  comprises a plurality of amplifiers  357 ,  360 ,  363 , and  366 . The output from rotary selector switch  41  connects to the positive (+) input of amplifier  357  through capacitor  351  and resistor  354 , along with the positive voltage feed  280  through a capacitor  369 , and a secondary ground  372  through a resistor  375 . The negative input (−) of amplifier  357  is connected to the output (o) thereof through a resistor  378 . The negative (−) input of amplifier  357  is also connected to secondary ground  372  through a resistor  381 . The negative (−) input of amplifier  360  is connected to the output (o) of amplifier  357  through a capacitor  384  and a resistor  387 . The positive (+) input of amplifier  360  is connected to secondary ground  372  through a resistor  390 . The negative input (−) of amplifier  360  is connected to the output (o) thereof through a resistor  393 . The output (o) of amplifier  360  is connected through a diode  396 , a resistor  399 , and a resistor  402  to secondary ground  372 , and through diode  396  through parallel resistor  405  and diode  408  to ground  272 . The output (o) of amplifier  360  is also connected through diode  396  and resistor  399  to the positive (+) input of amplifier  363 . The negative (−) input of amplifier  363  is connected through a switch  411  both to the negative (−) input of amplifier  366 , and through a switch  414  and diodes  417  and  420  to secondary ground  372 . Positive voltage feed  280  is also connected through diodes  417  and  420  to secondary ground  372 , but through a resistor  423 . The output (o) of each of amplifiers  363  and  366  are input to logic network  236  as square wave pulses.  
         [0041]    Logic Network: Logic network  236  comprises a plurality of OR gates  426 ,  429 ,  432 ,  435 ,  438 ,  441 ,  444 , and  447  which control the illuminating of the respective red, yellow, and green light assemblies  26 ,  29 , and  32 . The output (o) of amplifier  363  is connected to a first input ( 1 ) of OR gate  426  through a resistor  450 , and to ground  272  through a capacitor  453 . The collector of a transistor  456  is also connected to the first input ( 1 ) of OR gate  426 . The emitter of transistor  456  is connected to ground  272  and the base thereof is connected to speaker control circuit  242  through a diode  459  and a resistor  462 , and connected to ground through a resistor  465  and a capacitor  468 . The output (o) of OR gate  426  is connected through a capacitor  471  both to an input ( 1 ) of OR gate  429  and through a resistor  474  to positive voltage feed  280 . A second input ( 2 ) of OR gate  426  is connected to an output (o) of OR gate  429 , which connects respectively to diode  459 , to lamp output network  239 , and to a first input ( 1 ) of OR gate  438 . The output (o) of amplifier  366  is connected to a first input ( 1 ) of OR gate  432  through a resistor  477 , and to ground  272  through a capacitor  480 . The output (o) of OR gate  432  is connected through a capacitor  483  both to an input ( 1 ) of OR gate  435  and through a resistor  486  to positive voltage feed  280 . A second input ( 2 ) of OR gate  432  is connected to an output (o) of OR gate  435 , which connects both to a second input ( 2 ) of OR gate  438  and to a first input ( 1 ) of OR gate  447 . A second input ( 2 ) of OR gate  447  connects to ground  272  through a switch  489 . An output (o) of OR gate  447  connects through a switch  492  to respective first inputs ( 1 ) of OR gates  441  and  444 . An output (o) of OR gate  441  connects to a second input ( 2 ) of OR gate  444 , and through a pair of resistors  495  and  498  to a second input ( 2 ) of OR gate  441 . An output (o) of OR gate  444  connects to lamp output network  239 , and through a capacitor  501  to intermediate resistors  495  and  498  so as to connect through the respective resistors  495  and  498  to the respective second inputs ( 2 ) of OR gates  444  and  441 .  
         [0042]    Lamp Output Network: Lamp output network  239  comprises a plurality of transistors  504 ,  507 , and  510 , the respective bases of which are respectively connected to the output (o) of OR gate  429 , the output (o) of OR gate  444 , and the output (o) of OR gate  438 , through respective resistors  513 ,  516 , and  519 . The emitters of each transistor  504 ,  507 , and  510  is connected to ground  272 , and the collectors thereof are respectively connected to the red, yellow, and green light assemblies  26 ,  29 , and  32  for respective illumination of the light bulb  167 . Each of light bulbs  167  is also connected to the positive voltage output of rectifier bridge  257 .  
         [0043]    Speaker Control Circuit: The speaker control circuit  242  includes a first transistor  522 , the base of which is connected to diode  459  of logic network  236  connecting through resistor  462  to the base of transistor  456  thereto. A resistor  525 , a diode  528 , and sound on/off switch  50  are disposed between diode  459  and transistor  522 , switch  50  allowing the electrical power to speaker control circuit  242  to be cut to allow operation of noise level indicator  20  in a visual mode only if desired. The collector of transistor  522  is connected to the positive voltage output of rectifier bridge  257 . The emitter of transistor  522  is connected directly to a first connection ( 1 ) of an integrated circuit  531 , and through a resistor  534  to a second connection ( 2 ) of integrated circuit  531 . The emitter of transistor  522  is connected to an emitter of a second transistor  537  through a resistor  540 , and to a first connection ( 1 ) of speaker  188  through resistor  540 , a resistor  543 , and a capacitor  546 . Integrated circuit  531  at a third connection ( 3 ), and the emitter of transistor  522  through resistor  540  are connected to ground  272 . A fourth connection ( 4 ) of integrated circuit  531  connects to the base of second transistor  537  and to the connection from the collector of transistor  522  to microphone  188  intermediate resistor  543  and capacitor  546 . The collector of transistor  537  connects to the first connection ( 1 ) of speaker  188 . A second connection ( 2 ) of speaker  188  connects through a resistor  549  to the positive voltage output of rectifier bridge  257 . Speaker  188  provides an audio sound signal to persons in addition to the visual signal sent through the red, yellow, and green light assemblies  26 ,  29 , and  32 .  
       CONCLUSION  
       [0044]    It can now be seen that the present invention solves many of the problems associated with the prior art. The present invention provides an attractive, attention-getting design for a noise level indicator. The present invention provides feedback in a fin and interesting way so people use it. The present invention provides auxiliary attention-getting features including flashing light and sound. The present invention provides an adjustable sensitivity level to indicate the particular decibel level of the noise desired by the individual user as indicated by the lights and sounds. The present invention provides the flexibility to be placed on a table or hung on a wall to maximize visibility.  
         [0045]    Although the description above contains many specifications, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of presently preferred embodiments of this invention. The specification, for instance, makes reference to specific circuit designs. However, obviously there are many ways to design electrical circuits to accomplish the functions of the noise level indicator. Likewise, while the preferred form of the housing of the noise level indicator is that of a traffic light, other attention-getting housings can be used such as other road or construction signs, statues, and sculptures. Likewise, the lights can be used exclusive of sounds and vice-versa such as a statue incorporating the sounds but not the lights. Also, the microphone and power supply can be integral or separate plug-in devices to the housing. Thus, the scope of the invention should be determined by the appended claims and their legal equivalents rather than by the examples given.