Introduction to Auditory Graphs
## Introduction to Auditory Graphs

Before the test begins, a short explanation about Auditory graphs is
necessary for those who will be listening to the graphs instead of seeing
them. **It is a random process as to who gets which graph type**,
so everyone should understand how to listen to these graphs.

The basic auditory graph involves mapping the Y axis data to pitch, and
the X axis data to time. So the greater the Y value, the higher the
frequency of the sound, and the greater the X value the later the sound
will be played. As an example, in the following graph there are two
(X,Y) data points: (1,1) and (2,4). The (1,1) point can be heard first,
and has a low tone, the (2,4) point is played second and has a higher
tone.

Please play this graph now.
Note: The concept of 0 is difficult to represent in an auditory graph.
We have used the following tone to represent 0 in all of the graphs
in this test:

For most of the graphs that you will encounter, the lowest tone played
will represent 0.

A series of points would be played as a series of tones. The following
graph gives an example of a series of points that increase in both X and
Y values:

Please play this graph now.

In previous studies, it was noticed that it is difficult to tell when a
graph is linearly increasing (i.e. Y = X), vs. when there is some
curvature to the graph (i.e. ).
For this reason, a
sound to alert the listener to the slope and curvature of a graph has been
added. This sound is heard as a series of "drum" beats.
The slope of a graph is defined as the rise/run or . The
greater
the slope, the more rapid the beat.

Please listen to the
following graphs to determine which one has the greatest slope.

1:

2:

(The second graph has a greater slope)

The pitch of the drum beat indicates the curvature of the graph. The
curvature is defined as the change in the slope, or .
When the
curvature is positive ( ), as it is
for the graph of ,
the graph is
bowl shaped, and is represented with a low pitched drum beat. This graph
looks and sounds like the following:

Please play this graph now.
When the curvature is negative ( ) as in , the
graph is hat, or hill shaped. This type of graph has a high pitched
drum beat. This graph looks and sounds like the following:

Please play this graph now.
When there is no curvature ( ), as was
seen in the linear graphs above,
(remember, the graph can still have a non-zero slope) the pitch of
the drum beat is between those of the positive or negative curvature
graphs.

If you would like to see and hear more examples, please go to the
Sonitype page.

If this method of auditory graphing is clear, you're ready to

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