What comes What comes next?next?

O T T F F S S E N _?O T T F F S S E N _?

Tractor PullTractor Pull

What type of things will you What type of things will you see?see?

What type of tractors could be What type of tractors could be there?there?

How do tractor pulls work?How do tractor pulls work? What type of tools are needed?What type of tools are needed? What are some of the Safety What are some of the Safety

concerns of attending?concerns of attending?

Can You Hear Can You Hear Me Now?Me Now?

Measuring Noise LevelsMeasuring Noise Levels

What causes sound?What causes sound?

How can you measure noise How can you measure noise levels?levels?

Sound is measured in what Sound is measured in what units?units?

Can you name some events or Can you name some events or loud noises that causes your loud noises that causes your ears to ring?ears to ring?

Does the amount of time that Does the amount of time that you are exposed to this noise you are exposed to this noise determine if your ears ring?determine if your ears ring?

Does distance affect the sound Does distance affect the sound intensity?intensity?

Can loud sounds cause Can loud sounds cause permanent damage to hearing?permanent damage to hearing?

How can you find out what How can you find out what level you can safely listen to a level you can safely listen to a specific sound?specific sound?

What is OSHA?What is OSHA?

Occupational Safety Health Occupational Safety Health AdministrationAdministration

OSHA assists in determining OSHA assists in determining work place safety.work place safety.

What is a dB?What is a dB?

Duration of sound permitted Duration of sound permitted at at

various sound levels.various sound levels.With out hearing protectionWith out hearing protection

Duration in HrsDuration in Hrs Sound Level in Sound Level in dBdB

3232 80801616 858588 909044 959533 979722 1001001.51.5 10210211 1051050.50.5 1101100.250.25 115115none with outnone with out OVER OVER

115 115 hearing protectionhearing protection

What sounds are over 115 dB?What sounds are over 115 dB?

How can you be around noise How can you be around noise levels over 115 dB safely?levels over 115 dB safely?

What is NRR?What is NRR?

Noise reduction ratings.Noise reduction ratings.

Decibel (dB) Levels of Common Sounds at Typical Distance From Source

0 Acute threshold of hearing15 Average threshold of hearing20 Whisper30 Leaves rustling, very soft music40 Average Residence60 Normal speech, background music70 Noisy office, inside auto @ 60 mph80 Heavy traffic, window AC85 Inside acoustically insulated

protective tractor cab in field.90 OSHA limit—hearing damage on

excess exposure to noise above 90 dB.100 Noisy tractor, power mower,

ATV, snowmobile, motorcycle, in subway car, chain saw

120 Thunderclap, jackhammer, basketball crowd, amplified rock music.

140 Threshold of pain—shot gun, near a jet taking off, 50 hp siren (100’)

1. What is the graph about?

2. What is it comparing?

3. How many milk cows were there in the U.S. in 1993? What about 2002?

4. What is the dependent variable?

5. What is the independent variable?

6. According to the graph, there has been a 5% decrease in milk cows over

the last 10 years. Is that a significant decrease? Does the line actually look like only 5%?

Is this the same as the previous graph?

According to the previous graph, milk production decreased by 5% but the number of dairies decreased by 41%. How can this be?

1. Using the information given on the handout “Duration of Time Permitted At Various Sound Levels”, construct a line graph. Use “Sound Levels in dB” as your x values (independent variable) and the “duration” as your y values (dependent variable).

Y Axis ….

Dependent Variable

X Axis....

IndependentVariable

2. Using a decibel meter, record the dB levels of 10 different sounds. Construct a bar graph of the information obtained.

How to use the dB How to use the dB metermeter

Identify the sound recordedIdentify the sound recorded Set the range on the meterSet the range on the meter Read the sound levelRead the sound level If the meter says LO move the If the meter says LO move the

dial to a lower rangedial to a lower range If the meter is maxed out move If the meter is maxed out move

the range higherthe range higher Record your dataRecord your data

Examples of different Examples of different types of graphs.types of graphs.

1. What is the graph about?

2. What is it comparing?

3. Why do you think the eastern part of the US has such small farms?

4. Look at the states with the largest farms. What do they have in common?

5. Texas is a large state, so why do you think the average size farm is

smaller there than in New Mexico?

6. Why do you think that Oklahoma’s farms are smaller than the two states above and below us?

Are there any Are there any questions about questions about sound levels or sound levels or reading graphs?reading graphs?