The Science of Sound
The Science of Sound
The Science of Sound
Sound is energy
caused by vibration
that creates waves.
Energy
• Energy is the ability to do work or move an object with force.
• Sound moves the air (or matter) around us.
• Sound occurs when an object is vibrated by force.
• Sound is a type of energy.
Vibration
For sound to be produced, an object (or matter) needs to be vibrated or
moved by a force.
Sound Waves
The initial force used to make a sound vibrates the matter, surrounding it
in a chain reaction and creating waves.
How Are Sounds Different from
Each Other?
wavelength
amplitude
amplitude
trough
The Relationship Between Pitch,
Frequency, and Wavelength
Pitch is the highness or lowness of a sound.
Although the waves
Frequency is the number of peaks of waves in a specific time period. The
have different
more peaks in this time, the higher the pitch.
Wavelength is the distance between two peaks or two troughs of waves. A
amplitudes, their
--------
--------
higher-pitched sound has a shorter wavelength.
wavelength
High-pitched soundsishave
thehigh frequencies (more waves occurring in a
same.
given Therefore,
amount of time).
High-pitched sounds have shorter wavelengths.
they have
Low-pitched thehave
sounds same
low frequencies (a smaller number of waves
occurring in a given amount of time).
pitch.
Low-pitched sounds have longer wavelengths.
Volume
amplitude
------------------------------
• Volume is proportional to the amplitude of the sound wave. It is how
loud or soft a sound is.
• Amplitude is the measurement of wave displacement from its resting
position. It can be measured from rest to peak or from rest to trough.
• Lower amplitude, like the wave on the left, means lower volume.
• Higher amplitude, like the wave on the right, means higher volume.
Measurement of Sound: Volume
In conjunction with our nerves and brain, our eardrums let us know that
we hear a sound.
Animals’ Hearing
Elephants
Human
Some can
earsdetect
canand
dolphins detect
even lower
batsa can
range
frequencies
of frequencies
hear than humans
of
up20
to – 20,000
(from Hz.
120,000 14
Hz.Hz).
Ultrasound and Infrasound Waves
Ultrasound waves have frequencies too high for humans to hear and
shorter wavelengths than other sound waves.
Ultrasound waves can reflect more easily than other sound waves. They
are useful in:
non-destructive
medical testing of medical
imaging uses sonar
mechanical
equipment
Infrasound waves can record earthquakes that humans may not feel.
Sound Scientist