What Is a Sound Wave?
“Wave” is the descriptor given to phenomena that propagate themselves through space in ways like the waves in a puddle or sound waves or electromagnetic waves. If you were to draw a line from a sound source to your ear (for example) and measure the air pressure at different points along that line, the pressure would vary in a pattern that reflects the sound. If the sound was a pure note at a particular pitch and volume, the shape of the graph of the air pressure along the length of line at an instant in time would be a sine wave – which means it looks like a graph of the function y=sin(x). A “sound wave” could be one of these cycles of higher/lower pressure, but some use the term to refer to the shape of the graph of the sound (pressure variation) over time. We perceive the difference between the high and low pressure as “volume,” or how loud, and typically measure this sound pressure level (SPL) in bels or decibels (dB). If you could “see” these pressure variations they would look lik
A sound wave is a type of pressure wave caused by the vibration of an object in a conductive medium such as air. When the object vibrates, it sends out a series of waves which can be interpreted as sound. For example, when someone hits a drum, it causes the membrane of the drum to vibrate, and the vibration is transmitted through the air, where it can reach the ear of a listener. Not all sound waves are in audible range. Humans hear around 12 Hz to 20 kHz, meaning that sounds above and below this range cannot usually be heard, and some animals can hear at higher and lower ranges. Some sound waves move as transverse waves, moving in a classic wave-like pattern outwards from the origin of the sound. The movement of the wave is perpendicular, and could be compared to dropping a rock in the water and watching the outward ripple effect. They can also present as longitudinal waves, in which the movement is horizontal, creating alternate areas of compression in the medium to generate sound. L
How can a sound wave be measured? Frequently sound is described using terms such as pitch, tone, frequency, intensity or loudness. To understand the origins of these terms as well as to understand the mathematical models used to represent sound, this investigation can help you to explore the dynamics of a sound wave. The physical model has been simplified to highlight important scientific and mathematical features. Subsequent investigations will explore additional complexities of a sound wave. The sound wave is controlled by two parameters: the amount of initial energy put into the string (initial displacement) and the amount of tension in the string. The animation of the string has been slowed down so that model of the wave can be observed clearly.
A sound wave is produced by a mechanical vibration, such as a tuning fork. The vibrating object causes the surrounding medium, such as air, to vibrate as well. The wave travels through the medium to a detector, like your ear, and it is heard. As with any type of wave, a sound wave is also described by it’s wavelength, amplitude, period, and frequency. http://www.school-for-champions.com/science/sound.htm WAVELENGTH is the distance from one point on the wave, to the next identical point, or the length of one part of the wave. AMPLITUDE is the distance from the midpoint to the place of maximum displacement. FREQUENCY is the number of cycles that occur in one second. It is also the inverse of the period. PERIOD is the time it takes for a wave to complete one full cycle. It is also the inverse of frequency.
