Questions: Challenge questions which the
Messing Around research is designed to answer.
Tools & Materials: List and description
of tools and materials needed for Messing Around.
Activities: Hands-on activities
which are components of the Messing Around research.
Background
While you are messing around with sound, you will build some important equipment
for studying sound. At the same time, you will make important connections
between what you hear and the sound waves that produce the mental sensation
of sound. You will focus on three characteristics
of auditory perception: pitch, loudness, and quality. You will try to
connect these characteristics with five characteristics
of waves: frequency, period, wavelength, amplitude, and waveform.
On the physical level, sound as a mental experience is produced by an interacting
array of discharging neurons in the brain. In contrast, a sound wave is
a series of small density shifts (compressions and rarefactions) moving
through a medium away from a vibrating source. The human ear, a marvelously
versatile detector, converts sound waves into electrical signals which ultimately
produce the sensation of sound. While they are not the same, the sensation
of sound does convey information about the sound waves which produce it.
That will be our focus while we mess around with sound.
What are the connections between sound waves and the subjective impressions
which they create in the mind of a listener? After some messing around with
Pitching Practice, mess around with some real objects that ring, screech,
hum, or toot. Found sounds are usually uncontrollable. Their pitch, loudness,
and timbre are pretty much fixed. Science generally tries to bring some
kind of order to what it investigates. In the next part of messing around
with sound you will build electronic tools which will allow you to control
sound. The sound generator you'll make allows you to plan the frequency
and loudness of sounds it generates.
Focus
Reading about focus in a section titled "Messing Around" may seem
a little contradictory. It is not to most scientists. The difference between
messing around and experimenting is not the difference between play and
work or the difference between fun and drudgery. Most scientists enjoy their
work. It can be drudgery (like any job), but usually it has an element of
play and fun. For many scientists, the difference between messing around
and experimenting is precisely a matter of focus. When scientists mess around,
they usually have a broad focus. When they formally conduct an experiment,
they usually have a narrow focus. So, what should your focus be in this
section?
If you want to use sound, it helps understand what sound is. To start, let's
focus on the difference between sound as a mental experience and sound waves.
This distinction may not seem important, but it is very useful to anyone
who studies or uses sound.
Questions
Which pitch (frequency) is higher?
Do two sounds have the same quality?
How do you create well-controlled sounds electronically?
