The concept of sound is extremely complicated as well as technical. There are several components of sound, such as pitch, loudness, and waves. To begin we must understand that vibrations cause all sounds. When a sound is made such as a bell or a hand clapping, the vibrations from the sound bounce off surrounding particles such as air. As the waves pass through the air the particles in the air vibrate as well moving forward and backwards. A sound wave like all waves can carry energy from one place to another. There are three specific aspects of a sound wave. The first is the wavelength. This represents the length of one cycle of sound. It is the length in space of a sound. The period of a sound wave is the time taken for one wavelength to pass a certain point before a new wave begins. A longer wave period represents a lower pitch sound. The third part of a sound wave is the amplitude. The amplitude of a sound wave represents the loudness of the sound. The higher the amplitude, the louder the sound. (School for Champions/Science/Sound, 6/10/03)
Another important dimension of sound waves is their frequency. Frequency of a wave refers to how often a wave passes through a specific location. Frequency is measured by the number of complete back and forth vibrations of a particle. The frequency of a sound wave is measured in cycles per second, or Hertz.
1 Hertz = 1 vibration/second
Sound travels at 330 meters per second or 740 miles per hour.
740 mile/ hour = 330M/s x 3.3 Ft./M x 1 mile/5280 ft x 3600/hr
A sound wave will vibrate at different rates, which is the frequency of a wave. The faster an object vibrates, or higher the frequency the higher the pitch of the sound. A high pitch sound will have a high frequency, while a low pitch sound will have a low frequency. The shorter a wavelength appears the faster the object is vibrating and the frequency will be higher. If a wavelength is spread apart the slower the objects vibrating, and the frequency is lower. A mathematical calculation for this is shown with the formula:
D = s / f
D = wavelength in meters
S = Speed in meters per second
F = frequency in cycles per second, also called Hertz (Hz)
(figure available in print form)
Sounds are heard by the ear as either being loud or soft. The loudness of a sound in measured in decibels. Decibels refer to the energy produced by that sound. A human can hear sounds ranging from 0.1 decibels, which is very soft, to sound which measure 120 decibels. Younger people can often hear lower volumes better than older people. (School for Champions/Science/Sound, 6/20/03)