Sounds can change in shrillness or deepness-
that is, in their pitch. When we hear changes in pitch, it means that
the sound waves coming to our ears are changing in frequency. Frequency
is the number of sound waves that occur in one second. The higher the
frequency is, the higher the pitch will be. The lower the frequency is,
the lower the pitch will be.
High Frequency Wave
Low Frequency Wave
The chart below compares characteristics of musical instruments
with whether their pitch is high or low. A high frequency wave produces
a high pitch while a low frequency wave produces a low pitch.
Use the chart above and your observations of each picture.
Determine if the instrument would normally produce a high pitch or a low
2. Bass Drum
Highlight the box below to check your answers.
1. High pitch 2. Low pitch 3. High pitch 4. Low pitch 5. Low pitch
6. High pitch
Do the following activity to determine
what the size and shape of a vibrating object has to do with its pitch.
Small box (shoe box, wooden box) open at the top
Rubber bands that vary in lengths and thickness
Using only one rubber band, put the rubber
band around the box so it stretches across the opening at the top. Pluck
the rubber band.
Next, tighten the band by pulling it tight from underneath
the box. Keep it tight and pluck the rubber band again. Record
your observations in your science journal.
Place several rubber bands of the same lengths but different
widths on the box and pluck each of them. Again, record your
observations in your science journal.
Place bands of the same thickness but different lengths, around
the box and pluck each band. Once more, record your observations
in your science journal.
What is the relationship of the size and shape of
the vibrating rubber band to the pitch it produced?
List some instruments that prove your conclusion and
how each instrument changes pitch.