Practice ball with sound and acceleration sensor

A practice ball responsive to acceleration for use in practicing sports and an acceleration sensor therefor. The practice ball includes an electronics housing; an acceleration sensor mounted in the electronics housing and responsive to acceleration of the practice ball; a sound generating device also mounted in the electronics housing and responsive to the acceleration sensor; and a soft deformable shell having a shape which simulates a sports ball. The soft deformable shell, which is capable of snugly accommodating the electronics housing, may be supported by a tether line connected to the electronics housing. The acceleration sensor preferably includes at least two switching elements, each of which is responsive to a different magnitude of acceleration. The sound generating device is then responsive to the switching elements so as to emit different programmed sounds depending on which of the switching elements is/are actuated by acceleration of the practice ball. The different programmed sounds may include verbal messages from a voice simulation device in the sound generating device. Preferably, the practice ball is a soft, foam soccer ball for use in practicing the art of heading a soccer ball.

BACKGROUND OF THE INVENTION 
The present invention relates to a ball capable of emitting different 
sounds in response to different accelerations, for use in sports training 
especially in practicing the art of heading of a ball important in playing 
the sport of soccer, also known elsewhere in the world as football. The 
present invention also relates to an acceleration sensor capable of 
detecting at least two different magnitudes of acceleration. 
There are many known practice devices for improving one's skills at a sport 
such as soccer including devices for training in heading soccer balls. The 
following are several examples of soccer practice devices: 
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Patent No. Patentee 
______________________________________ 
4,561,661 Walker et al. 
4,576,379 Juhasz 
4,706,964 Genovese 
5,083,797 Vartija et al. 
5,280,843 Vartija et al. 
5,358,258 Killion 
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In addition, there are several patented ball-shaped toys which include 
sound-generating devices for emitting sounds when keys on the outer 
surface of the device are manually activated. The following are examples 
of such ball-shaped toys: 
______________________________________ 
Patent No. Patentee 
______________________________________ 
5,049,107 De Nittis 
5,260,512 Chomette et al. 
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None of the foregoing devices, however, provides a practice or training 
ball capable of emitting a programmed sound in response to the impact 
imparted to the ball by the practicing or training person. Moreover, none 
of the foregoing devices provides a practice ball capable of emitting 
different sounds in response to different magnitudes of impact imparted to 
the ball upon being struck. More particularly, none of the prior art 
devices when tethered for training the art of soccer heading are capable 
of emitting a programmed sound depending upon the impact characteristics 
delivered to the tethered ball by the practicing person. An arrangement 
capable of performing these functions would be extremely useful for 
indicating to an athlete whether a simulated ball was struck with 
sufficient force to a achieve a desired acceleration of the ball, 
especially in training proper heading of a soccer ball. 
SUMMARY OF THE INVENTION 
A primary object of the present invention is to overcome the deficiencies 
in the prior art training devices, especially tethered training balls, by 
providing a practice ball capable of emitting a programmed sound or sounds 
in response to the impact imparted to the ball upon being struck. 
Another object of the present invention is to provide a practice ball 
capable of emitting different programmed sounds in response to different 
magnitudes of impact imparted to the ball. 
A further object of the present invention in accordance with the foregoing 
objects is to provide a practice ball which measures impact based upon the 
amount of acceleration imparted to the practice ball by the training 
person and to emit a programmed sound or verbal message characteristic of 
the amount of measured acceleration. 
A still further object of the present invention is to provide a tethered 
ball simulating a soccer ball for training the art of soccer heading which 
is capable of emitting a programmed sound depending upon the impact 
characteristics delivered to the tethered ball by the practicing person. 
Yet another object of the present invention is to provide an impact sensing 
mechanism for use in a practice ball, specifically in acceleration sensor, 
which is responsive to at least two different magnitudes of acceleration. 
Still yet another object of the present invention is to provide a compact 
housing assembly for mounting the impact sensor, sound emitting speaker 
and related components to be inserted and retained in the practice ball in 
accordance with the preceding objects. 
Still a further object of this invention is to provide a programmed sound 
emitting practice ball in accordance with the preceding objects which will 
be of simple construction, readily manufactured from available components, 
and easy to use so as to provide a device that will be economically 
feasible, long lasting, and relatively trouble free in operation. 
The above and other objects are achieved by the practice ball and impact 
sensor of the present invention. The practice ball includes an electronics 
housing, an impact sensor in the form of an acceleration sensor mounted to 
the electronics housing which is responsive to acceleration of the 
practice ball, a sound generating mechanism mounted to the electronics 
housing and responsive to the acceleration sensor for emitting at least a 
first sound in response to a first predetermined minimum amount of 
acceleration, and a soft shell having a shape which simulates a sports 
ball, preferably a soccer ball, and capable of accommodating the 
electronics housing. 
Preferably, the simulated sports ball is a ball of deformable cellulous 
material, such as polyurethane foam or the like, and has a cavity in its 
outer surface to receive the electronics housing therein. The housing and 
the cavity are preferably dimensioned such that the electronics housing 
fits snugly within the cavity and is retained in the cavity by the 
frictional engagement of the housing exterior walls and the deformable 
walls of the cavity. In addition, the surface of the electronics housing 
facing outwardly preferably has an open-cell cellulous covering which 
matches the spherical shape of the ball outer surface. 
The impact sensor in accordance with the present invention is an 
acceleration sensor which preferably includes at least two switching 
elements, each of which is responsive to a different magnitude of 
acceleration. The sound generating mechanism is responsive to the 
switching elements so as to emit different programmed sounds or verbal 
messages depending on which of the switching elements is/are actuated. 
Preferably, the acceleration sensor includes a conductive frame member 
having holes therein and electrically connected to the sound generating 
mechanism. The switching elements include springs, each of the springs 
having a distal end disposed through a respective one of the holes in the 
conductive frame member and a fixed proximal end electrically connected to 
the sound generating mechanism. The holes in the conductive frame member 
and the springs are arranged with respect to one another so that the 
springs make electrical contact with the conductive frame member only in 
response to different magnitudes of acceleration. Preferably, the springs 
are substantially parallel to one another and responsive to acceleration 
in any direction which is orthogonal to a longitudinal axis of each 
spring. 
The sound generating mechanism is responsive to electrical contact between 
the springs and the conductive frame member so as to produce different 
programmed sounds according to which of the springs makes the electrical 
contact with the conductive frame member. Preferably, the sound generating 
mechanism includes a voice simulation device and the different sounds are 
verbal messages. 
In the preferred form of the invention, the practice ball simulates a 
soccer ball and includes a tether line preferably connected directly to 
the electronics housing so that the electronics housing is supported by 
the tether line. When the tether line is so connected, the tether line 
supports the soft deformable ball by virtue of the snug fit of the 
electronics housing in the cavity of the ball. The acceleration sensor is 
adapted to distinguish between accelerations associated with an improperly 
headed soccer ball and accelerations associated with a properly headed 
soccer ball. The verbal messages are then selectively emitted depending on 
whether the accelerations correspond to a properly headed soccer ball or 
an improperly headed soccer ball. 
The foregoing, together with other objects and advantages which will become 
subsequently apparent, reside in the details of construction and operation 
as more fully hereinafter described and claimed, reference being had to 
the accompanying drawings forming a part hereof, wherein like numerals 
refer to like parts throughout.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
In describing the preferred embodiments of the invention as illustrated in 
the drawings and otherwise, specific terminology will be resorted to for 
the sake of clarity. However, the invention is not intended to be limited 
to the specific terms so selected, and is to be understood that each 
specific term includes all technical equivalents which operate in a 
similar manner to accomplish a similar purpose. 
With reference to FIGS. 1-6, a preferred embodiment of a practice ball 10 
for use in practicing sports, particularly for practicing the heading of 
soccer balls, will now be described. 
As FIG. 1 illustrates, the practice ball 10 includes an electronics housing 
12; an impact sensor 14, preferably an acceleration sensor, mounted to the 
electronics housing 12 via a circuit board 16; a sound generating 
mechanism 18 mounted to the electronics housing 12 and which includes the 
circuit board 16 and a speaker 19; and a soft shell 20 having a shape 
which simulates a sports ball, and capable of accommodating the 
electronics housing 12. 
While an acceleration sensor is the preferred embodiment for the impact 
sensor 14 and an acceleration sensor will be described further 
hereinafter, it will be appreciated by those skilled in the art that other 
impact sensing mechanisms can be designed and incorporated in accordance 
with the present invention. It should be appreciated that the sensing 
mechanism should sense a minimum level of impact and distinguish between 
at least a poor heading impact and a good heading impact in order to serve 
as a valuable training aid in the art of heading a soccer ball in 
accordance with the present invention. 
Preferably, the soft shell 20 for the simulated sports ball is made of a 
deformable cellulous material having a cavity 22 extending through an 
outer surface 24 of the ball. The cavity 22 is preferably dimensioned such 
that the electronics housing 12 fits snugly and remains frictionally 
retained therein. Although the preferred embodiment of the soft shell 20 
is made from a polyurethane foam having a closed-cell structure and having 
a density of approximately 3.5 pounds per cubic foot, it is understood 
that many other similarly resilient materials may be utilized. Preferably, 
the soft shell 20 simulates a soccer ball and has a diameter of 
approximately 7.5 inches. 
The cavity 22 is sufficiently deep to permit retention of the electronics 
housing 12 well below the outer surface 24 of the soft shell. The void 
left between the outer surface 24 and the electronics housing 12 is 
preferably filled using a cellulous foam cover 26 having an outer shape 
which matches the spherical shape of the outer surface 24. Preferably, the 
cellulous foam cover 26 has an open-cell structure so that sound passes 
more easily through the cover 26 from the sound generating mechanism 18. 
As illustrated in FIGS. 1-3, the electronics housing 12 is compact in size 
and preferably includes first and second cup-shaped members 13,15 which 
are interconnected to form a generally cylindrical enclosure. The two 
cup-shaped members 13,15 are readily secured together using fastening 
screws which extend through respective fastening holes 27 in cup-shaped 
member 15 into threaded engagement with internally threaded flanges 29 
which project radially inwardly and upwardly from the walls of the 
cup-shaped member 13 to thereby secure the two cup-shaped members 13,15 to 
one another. The flanges 28 extend above the top edge of member 13 to 
serve to guide members 13 and 15 into registry with each other. Batteries 
11 are preferably mounted inside the second cup-shaped member 15 and wires 
connect the batteries 11 to the circuit board 16. 
Alternatively, the two cup-shaped members 13,15 may be secured permanently 
to one another using any suitable technique, such as gluing, welding, and 
the like. When the two cup-shaped members 13,15 are permanently secured to 
one another and batteries are used to power the impact sensing and sound 
emitting mechanism, the batteries should not be mounted inside the 
electronics housing 12 unless the life of the practice ball 10 is to be 
limited to the life of the batteries. The electronics housing 12 may be 
manufactured using any suitable material, including aluminum, plastic, and 
the like. Preferably, the electronics housing 12 includes a plurality of 
holes 17 in the bottom surface of the first cup-shaped member 13 to 
facilitate sound emission through the housing 12 from the speaker 19. The 
speaker 19 may be of any known manufacture and is preferably a 21/2 inch 
mylar speaker. 
The acceleration sensor 14 is responsive to acceleration of the practice 
ball 10. The sound generating mechanism 18, in turn, is responsive to the 
acceleration sensor 14 so as to emit a particular sound in response to a 
predetermined amount of acceleration. Preferably, the acceleration sensor 
14 is a switch having at least two switching elements 28,30, each of which 
is responsive to a different magnitude of acceleration. The sound 
generating mechanism 18 is responsive to the switching elements 28,30 so 
as to emit different sounds depending on which of the switching elements 
28,30 is/are actuated. 
When the practice ball 10 is utilized, for example, to practice the art of 
heading a soccer ball, the switching element 28 which responds to the 
larger magnitude of acceleration is calibrated to activate only when the 
magnitude of acceleration corresponds to that which is created when the 
soccer ball is properly headed. The other switching element 30 is 
calibrated to activate when the magnitude of acceleration corresponds to 
at least the amount of acceleration generated when a soccer ball is 
improperly headed. When insufficient impact is imparted to the ball to 
correspond to at least the minimum amount of acceleration to activate 
switching element 30, no sound is emitted. 
With reference to FIG. 4, the acceleration sensor 14 preferably includes a 
conductive frame member 32 having holes 34,36 formed therein. The 
conductive frame member 32 defines a first electrical node which is 
electrically connected to the circuit board 16 of the sound generating 
mechanism 18, preferably to the electrical ground thereof. Although the 
conductive frame member 32 is preferably made of brass, it is well 
understood that virtually any other electrically conductive material will 
suffice. 
Each of the switching elements 28,30 includes a spring 38,40. Each of the 
springs 38,40 has a distal end disposed through a respective one of the 
holes 34,36 in the conductive frame member 32 and a fixed proximal end 
electrically connected to the circuit of the circuit board 16 in the sound 
generating mechanism 18. Each spring 38,40 defines an additional 
electrical node of the acceleration sensor 14. 
The holes 34,36 in the conductive frame member 32 and the springs 38,40 are 
arranged with respect to one another so that the springs 38,40 make 
electrical contact with the conductive frame member 32 only in response to 
different magnitudes of acceleration. Such responsiveness to different 
magnitudes of acceleration can be achieved by providing the holes 34,36 
with different diameters, or alternatively, by using springs 38,40 having 
different mechanical responses to acceleration, for example different 
"spring constants" or the like. The preferred diameters and spring 
constants, of course, depend on the intended use of the practice ball 10. 
For example, a practice ball 10 for use in practicing the art of heading a 
soccer ball would require less acceleration to generate a message than a 
practice ball which is used as a punching bag. 
The springs 38,40 are preferably parallel to one another and responsive to 
acceleration in any direction which is orthogonal to a longitudinal axis 
of each spring 38,40. Such acceleration in any orthogonal direction causes 
flexing of the springs 38,40, and when sufficient flexing occurs, 
electrical contact is established with the conductive frame member 32. 
Preferably, the conductive frame member 32 includes four legs 33, each of 
which is bent to assume a V-shaped configuration which fits snugly into 
respective connection holes in the circuit board 16. It is understood that 
the walls of the respective connection holes include a conductive material 
which electrically connects the legs 33 to the circuitry of the circuit 
board 16. However, other convenient methods for attaching the frame member 
32 to the circuit board 16 can be utilized. 
When the acceleration sensor of FIG. 4 is utilized, the sound generating 
mechanism 18 is made responsive to electrical contact between the springs 
38,40 and the conductive frame member 32 so as to produce different sounds 
according to which of the springs 38,40 make/makes electrical contact with 
the conductive frame member 32. 
A preferred circuit for placement on the circuit board 16 of the sound 
generating mechanism 18 is illustrated in FIG. 5. The circuit includes a 
voice simulation device for generating a plurality of different verbal 
messages in response to different accelerations of the practice ball 10. 
According to a preferred circuit arrangement, the voice simulation device 
includes a power circuit 42; a reset pulse generator 44; a microprocessor 
IC 46; a crystal oscillator circuit 48; a low-pass filtering circuit 50 
with a cut-off frequency of approximately 3.5 kHz; an amplifier power 
switch Q8; an amplification circuit 52; and the speaker 19 of the sound 
generating mechanism 18. 
The following table correlates the various illustrated circuit elements in 
FIG. 5 with the preferred characteristics thereof: 
______________________________________ 
REF. NO. DESCRIPTION OF PREFERRED CIRCUIT ELEMENT 
______________________________________ 
C1 Capacitor: 10 .mu.Farad with at least a 10 V rating 
C2 Capacitor: 220 .mu.Farad 
C3, C4 Capacitor: 33 Pfarad 
C5, C6, C7 
Capacitor: 0.1 .mu.Farad 
C8 Capacitor: 1.0 .mu.Farad 
C9 Capacitor: 0.1 .mu.Farad 
C10, C11 Capacitor: 0.022 .mu.Farad 
J1 Two-terminal electrical connector for 
electrically connecting the battery to the 
circuit when the slide switch is used 
J2 Two-terminal electrical connector for 
electrically connecting the battery to the 
circuit when the slide switch is not used 
J3 Two-terminal electrical connector for 
electrically connecting the speaker 19 to the 
circuit board 16 
D1, D2 Diodes, preferably RLS4150 surface mounted diodes 
with a 1 amp rating 
S1 Push-button electrical switch, preferably 
mounted to an outside surface of the electronics 
housing 12 and preferably consisting of a 
membrane switch which closes only in response to 
an external force and otherwise remains open. 
The push-button electrical switch preferably is 
positioned on the housing 12 so that it can be 
actuated by pressing a portion of the cover 26 
which bears against the switch. 
S2 Slide switch for selectively electrically 
connecting the circuitry to the power supply, the 
slide switch having a closed position and an open 
position 
Q6 Transistor: PNP transistor, preferably, Part No. 
4403 manufactured by Motorola 
Q7, Q8 Transistor: NPN transistor, preferably, Part No. 
4401 manufactured by Motorola 
R1, R2 Resistors: 47 k.OMEGA. 
R3, R4, Resistors: 2 k.OMEGA. 
R9, R13 
R5, R10, Resistors: 47 k.OMEGA. 
R11 
R12 Resistor: 470 .OMEGA. 
46 Microprocessor IC: preferably, TSP50C11 
microprocessor IC manufactured by and 
commercially available from Texas Instruments 
with an internal speech synthesis circuitry. 
The various pin designations and connections of 
these pins to the circuitry are illustrated. 
U2 Amplifier IC: preferably, LM386 amplifier IC 
manufactured and commercially available from 
National Semiconductor. The various pin 
designations and connections of these pins to the 
circuitry are illustrated. 
Y1 9.6 MHz crystal 
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As illustrated in FIG. 5, two test points TP1,TP2 are provided for 
monitoring the voltage Vcc across the circuit. These test points TP1,TP2 
are merely optional and therefore may be omitted in a commercial 
embodiment of the invention. Likewise, the slide switch S2 may be omitted 
so that voltage from the battery box 11 is constantly applied to the 
circuitry illustrated in FIG. 5. When such an arrangement is used and the 
practice ball 10 is not in use, the microprocessor 46 is programmed to 
assume a STANDBY mode during which only a minimal amount of power is 
required. The drain on the batteries is therefore insignificant, even 
though the circuitry remains electrically connected to the battery box 11. 
In the STANDBY mode, the circuitry illustrated in FIG. 5 draws less than 10 
micro-amps of current. A single 6 volt battery arrangement consisting of 4 
AAA alkaline batteries therefore is capable of providing enough power to 
maintain the STANDBY mode for at least 110,000 hours and is also capable 
of emitting approximately 39,600 messages. When 4 AAA heavy-duty zinc 
batteries are substituted for the alkaline batteries (to reduce cost), 
there is enough energy to maintain the STANDBY mode for at least 66,000 
hours and enough energy to generate 23,000 messages. 
With such low levels of power consumption, it is commercially feasible to 
manufacture and sell the practice ball 10 with a permanently closed 
version of the electronics housing 12 so that the life of the practice 
ball 10 is limited to the life of the batteries. Such an arrangement 
advantageously permits the manufacturing and commercialization of the 
practice ball 10 without having to provide subsequent access to the 
electronics housing 12 through the soft shell 20. Thus, the cover 26 may 
be permanently glued into the soft shell 20 or otherwise formed integrally 
therewith. 
Preferably, the microprocessor 46 of the voice simulation device is 
programmed to carry out the steps illustrated in the flow chart of FIG. 6. 
Although the flow chart includes some assembly language instructions, it 
is readily understood that any other suitable programming language may be 
utilized depending on the capabilities of the particular microprocessor 
utilized. 
Initially, when battery power is applied to the microprocessor 46 (step 
100), an initialization process (step 102) is carried out. Such 
initialization processes are generally known and include resetting of the 
microprocessor's internal RAM. 
Next, the microprocessor 46 checks its terminal to determine whether 
the terminal has been grounded by one of the switching elements 28,30 
(step 104). Of the two switching elements 28,30 in the acceleration sensor 
14, the terminal is connected to the switching element 28 which 
responds to the larger magnitude of acceleration (hereinafter "level 2" 
acceleration). The terminal is therefore grounded only when the larger 
magnitude of acceleration is achieved. 
If the terminal is grounded, the microprocessor 46 checks one of its 
internal memory locations CNT.sub.-- 2 in RAM to determine whether the 
value stored therein is greater than three (step 106). If this value is 
greater than three, then the microprocessor 46 determines that the 
previous three consecutive accelerations have reached or exceeded the 
level 2 acceleration. The microprocessor 46 therefore resets the value in 
the internal memory location CNT.sub.-- 2 to one (step 108), and a first 
predetermined message is verbally delivered via the filtering circuit 50, 
amplification circuit 52 and the speaker 19 (step 110). Preferably, the 
first predetermined message is "Goal|", with a long and drawn out 
pronunciation and Spanish accent which simulates a famous World Cup soccer 
announcer. 
If the terminal is grounded, but the value in the memory location 
CNT.sub.-- 2 is not greater than three, then the memory location 
CNT.sub.-- 2 is incremented (step 112) and one of a second, third, and 
fourth predetermined messages is verbally emitted via the filtering 
circuit 50, amplification circuit 52 and the speaker 19 (step 114a, 114b, 
or 114c). Each of the second, third, and fourth messages indicates to the 
user that the practice ball 10 was hit hard enough to achieve the level 2 
acceleration. Preferably, the second predetermined message is "Great" 
(pronounced Ga-RR-ate| and lasting approximately 1 second). The third 
predetermined message is preferably "fantastic" (pronounced FF-an-TAstic| 
and lasting approximately 1.5 second). And, the fourth predetermined 
message is preferably "awesome" (pronounced AAW-some| and lasting 
approximately 1 second). The order of the second, third, and fourth 
messages may be determined by the value in the memory location CNT.sub.-- 
2, or alternatively, the second, third or fourth message may be randomly 
selected using the microprocessor 46 and one of various 
microprocessor-based random selection techniques which are generally 
known. 
After any one of the first, second, third or fourth messages is verbally 
delivered, the microprocessor 46 switches the circuitry to the STANDBY 
mode during which power consumption is significantly reduced. 
If, however, the microprocessor 46 determines in step 104 that the 
terminal is not grounded (i.e, the level 2 acceleration was not achieved), 
then the value stored in the internal memory location CNT.sub.-- 2 is 
reset to one (step 116). Next, the microprocessor 46 checks the 
push-button switch S1 to determine whether the switch S1 is closed (step 
118). 
If the switch S1 is closed, then a fifth predetermined message is verbally 
emitted via the filtering circuit 50, amplification circuit 52 and the 
speaker 19 (step 120). Preferably, the fifth predetermined message 
simulates a bugle playing a "charge" theme, followed by the trade name of 
the practice ball 10, for example, "HEAD COACH". Thereafter, the 
microprocessor 46 returns to the STANDBY mode. 
If the switch S1 is open during step 118, then one of a sixth, seventh, 
eighth and ninth predetermined messages is emitted via the filtering 
circuit 50, amplification circuit 52 and speaker 19. Each of the sixth 
through ninth messages signifies that, although the practice ball 10 was 
accelerated with sufficient magnitude to trigger a most responsive of the 
switching elements 28,30, the magnitude of acceleration did not reach the 
desired level 2 acceleration. Preferably, the sixth predetermined message 
is "Duh", using a pronunciation which simulates the voice of Cartoon 
Character Bart Simpson. The seventh predetermined message is preferably 
"Try Again|"; the eighth predetermined message is "Higher"; and 
preferably, the ninth predetermined message is "Harder", all of which last 
approximately 1 second. 
As indicated by step 122, when the switch S1 is not depressed in step 118, 
the microprocessor 46 preferably inserts a randomly selected numerical 
value in another internal memory location CNT.sub.-- 1 in RAM. The 
randomly selected number is selected from a group of numbers wherein each 
number corresponds to a particular one of the sixth through ninth 
predetermined messages. This random selection therefore randomly 
determines which of the sixth through ninth predetermined messages is 
delivered in steps 124a-124d. 
Alternatively, the internal memory location CNT.sub.-- 1 may be incremented 
after delivery of each of the sixth through ninth messages in a repeating 
order. According to this alternative arrangement, the repetition could be 
provided by resetting the CNT 1 memory location after the value stored 
therein reaches a predetermined maximum number. 
Whenever the microprocessor 46 is in the STANDBY mode, the and 
terminals are continuously monitored to determine whether the voltage on 
these terminals drops to ground. Since the terminal is connected to 
the push-button switch S1 and the terminal is connected to the most 
responsive of the switching elements 28,30, the microprocessor 46 will 
"wake-up" from the STANDBY mode only if one of two events occur (other 
than power failure). The first event is activation of the push-button 
switch S1 and the other event is acceleration of the practice ball 10 with 
sufficient magnitude to actuate the most responsive of the switching 
elements 28,30. Either of these events will cause the microprocessor 46 to 
re-initialize itself and perform the aforementioned operations beginning 
with step 104. 
According to the flow chart, one of the sixth through ninth messages is 
emitted immediately after power is initially applied to the microprocessor 
46 so long as the least responsive of the switching elements 28,30 is not 
activated, nor is the push-button switch S1 activated. In particular, upon 
initially receiving power, the microprocessor 46 performs step 102, step 
104, step 116, step 118, step 122 and one of steps 124a-124d. When the 
practice ball 10 is configured with a permanently closed electronics 
housing, the step of powering on the microprocessor 46 occurs only during 
manufacturing. Therefore, the extraneous sixth, seventh, eighth or ninth 
message occurs only during manufacturing. 
By using the circuitry illustrated in FIG. 5 and operating according to 
FIG. 6, the practice ball 10 is able to distinguish between accelerations 
thereof associated with an improperly headed soccer ball and accelerations 
associated with a properly headed soccer ball. The practice ball 10 is 
therefore able to selectively emit different messages depending on whether 
the practice ball is properly headed or improperly headed. 
As illustrated in FIG. 1, the practice ball 10 preferably includes a tether 
line 70 connected to and supporting the electronics housing 12. 
Preferably, the tether line 70 passes through a narrow slit 72 in the soft 
shell 20 and thereby supports the soft shell 20 via its passage through 
the soft shell 20 and by virtue of a snug fit of the electronics housing 
12 within the lower portion of the soft shell 20. 
The tether line is preferably attached to the electronics housing 12 so as 
to extend in a direction perpendicular to a top surface of the conductive 
frame member 32. In this way, the practice ball 10 is made sensitive to 
accelerations in any direction perpendicular to the tether line 70. 
The tether line 70 is preferably a 3/4 inch polyester strap arranged so as 
to form a loop 73. The loop 73 preferably includes a buckle arrangement 
and/or hook-and-loop fasteners which render the length of the loop 73 
adjustable. 
It is emphasized that the foregoing description of preferred embodiments is 
merely exemplary and that many modifications may be made without departing 
from the scope and spirit of the present invention. For example, the 
electronics housing 12 may have an outer surface which is positioned at 
the outer surface 24 of the soft shell 20 and which is pentagonally or 
hexagonally shaped to match a soccer ball pattern on the outer surface 24 
of the soft shell 20. 
Further, the soft shell 20 could be replaced by a more rigid structure or 
skin close to the feel of a soccer ball and the impact sensing and sound 
emitting mechanism could be retained within the shell by rigid mounting 
projections on housing 12 embedded with the shell material, or other 
mounting techniques. In addition, the electronics housing 12 may be 
connected to the tether line via the pentagonally or hexagonally shaped 
outer surface of the electronics housing. Therefore, it is not intended to 
limit the present invention to the embodiment disclosed, but rather is 
limited only by the full scope of the invention as described and claimed.