Making Sounds

Bettye J. Banks                Horace Mann Elementary School
                               8050 S. Chappel Ave.
                               Chicago IL  60617
                               (312) 535-6640

Objectives:

 The students will be able to:
 - observe that vibrating objects can produce sounds.
 - observe that the faster an object vibrates,the higher the sound or pitch.
 - observe the slower an objective vibrates, the lower the sound or pitch.

Materials needed:
  
Activity 1: 24 small mouthed glass bottles of comparable size, 4 metal spoons,
            1 large water pitcher and 4 funnels.
Activity 2: 30 wooden rulers with each student at his or her desk. 
Activity 3: 4 shoe boxes, 8 small pieces of plywood, 2 large bags of rubber
            bands and 4 pairs of scissors.    

Strategy:

Activity 1:             PLAYING THE RULER
Students will hold a ruler on a table with half its length over the edge. Pluck 
the end of the ruler and listen to the sound.  Now move the ruler so there is 
only a short length over the edge of the table and pluck it again.  Then try the 
same thing with a long length of ruler over the edge of the table.  As you move 
the ruler, what happens to the sound?  If more of the ruler is over the edge of 
the table, does the sound become higher or lower?  Then the students will 
record data from what they observed. 

Activity 2:             BOTTLE ORGAN
The students will identify how the height of an air column affects the pitch
of sound.  Students will work in groups, they will pour different amounts of
water in each bottle, bottles will be labeled A, B, C, D, E, and F.  Next, they 
will gently tap each bottle with the metal spoon to determine the difference in 
the pitch produced.  Then students will record data on a chart to show which 
bottle has the highest pitch. 

Activity 3:             RUBBER BAND GUITAR
Each student will be issued materials needed to make a rubber band guitar.
Students will take scissors and cut a hole in the middle of a shoe box.  Next,
stretching several rubber bands of various lengths and thickness across the
top of the box leaving a gap of about half an inch (1cm) between each one.
Students will pluck rubber bands to discover what sounds are vibrating.  Next 
they will add two pieces of wood about half an inch square as wide as the box.  
They are called the bridge.  Teacher will ask the questions: What happens when 
you pluck the bands without the bridge?  Is the pitch of the notes made by the 
looser bands higher or lower? Students will record data. 

Reference:

Kaner, Etta. Sound Science. Addison-Wesley Publishing Company, 1991