in the first configuration of the invention , a simplified device is made which analyzes vocal intensity ( volume or amplitude ) and vocal frequency , then presents this information as visual , tactile , and auditory feedback . the user wears a throat microphone . such microphones are made by enhanced listening technologies , of west palm beach , fla . ; and ceotronics , of germany . the microphone plugs into 3 . 5 mm jack . a resistor provides bias power to the microphone . a potentiometer provides microphone gain control , which sets the threshold level at which the feedback switches on or off . an op - amp ( a lm6042 , made by national semiconductor ) amplifies and filters the audio signal . a frequency - to - voltage converter ( a lm2907 , made by national semiconductor ) analyzes the audio amplitude and frequency , converting this into a dc signal . alternatively a rectifier can be used , to analyze amplitude without frequency . a rectifier consists of two diodes , and a resistor and capacitor to dampen the dc signal . the dc signal then goes to a comparator . a quad comparator ( lp339 , made by national semiconductor ) is used . the first comparator compares the dc signal to a fixed dc reference voltage . two resistors set the reference voltage , typically half of the circuit voltage . the output of the first comparator switches on a red led light , visually indicating that the user &# 39 ; s voice has exceeded the threshold . this output signal also goes to the input of the second comparator . the second comparator is set up as an inverter . the output of the second comparator drives a green led light . thus a single bicolor led displays as green when the user &# 39 ; s vocal intensity is below the threshold , and switches to red when the user &# 39 ; s vocal intensity exceeds the threshold . the output of the second comparator also goes to the input of the third comparator . this non - inverting comparator provides a higher current output for the vibrating motor . vibrating motors made by jinlong machinery are preferred , such as the 6sh1 - 0671a . this provides tactile feedback when the user &# 39 ; s vocal intensity exceeds a threshold . the fourth comparator is set up to synthesize a square wave at approximately 125 hz . this square wave is then smoothed by a group of resistors and capacitors into a pseudo - sine wave . this provides a pleasant tone . if a harsh sound is preferred as aversive stimulation , decreasing the value a capacitor increasing the frequency ; or decreasing the value of another capacitor reduces the smoothing of the signal . a switch enables the user to switch between hearing the tone or his / her voice . a power amplifier ( a lm4881 , made by national semiconductor ) provides this auditory feedback to a 3 . 5 mm earphone jack . a potentiometer provides a volume control . a voltage regulator ( lp2982 , made by national semiconductor ) provides the power supply . a 9 - volt battery is used for power , which is converted to five volts to run the circuit . to increase battery life , the circuit can also run at four volts . the entire circuit easily fits into a small case similar to a pager , which clips onto the user &# 39 ; s belt . the user may wear earphones to receive the auditory feedback . alternatively the user may forego wearing earphones and rely instead of the tactile and / or visual feedback . in a second embodiment of the invention , a frequency shifting computer chip , such as a yss222 - d , made by yamaha semiconductor , can be used to shift the user &# 39 ; s vocal signal higher or lower in pitch . when this chip is inserted into the circuit , the user can hear his or her voice sounding more relaxed or more tense . this altered auditory feedback can induce tense or relaxed vocal folds , thus actively inducing quieter , more relaxed speech ( or louder , tensor speech ), with little or no effort on the part of the user . in a third embodiment of the invention , a double - pole , double - throw switch is inserted between the frequency - to - voltage converter and the first comparator . this switch enables reverses all outputs , so that low vocal intensity is bad instead of good , or vice versa : e . g ., the green light that indicates low vocal intensity is switched so that the red light indicates low vocal intensity . in a fourth embodiment of the invention , one or two lcd clock modules are added . a red lion mdmu0000 lcd module is preferred . by connecting pin 2 of the lcd module to the output of the first comparator , the clock starts when the user &# 39 ; s vocal intensity exceeds the threshold . thus the clock displays the elapsed time that the user is screaming . a second clock module with pin 2 connected to main power displays the elapsed time that the device is on . thus a parent could tell a child that he &# 39 ; ll earn a reward if his elapsed time on the first clock is less than one hour . the second clock shows the parent that the child didn &# 39 ; t cheat by switching the device off and on to reset the first clock . thus , by utilizing the above construction , a device for monitoring vocal intensity is realized . it will thus be seen that the objects set forth above , among those made apparent from the preceding description , are efficiently attained and , since certain changes may be made in the above constructions without departing from the spirit and scope of the invention , it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative , and not in a limiting sense . it will also be understood that the following claims are intended to cover all of the generic and specific features of the invention , herein described , and all statements of the scope of the invention which , as a matter of language , might be said to fall therebetween .