An oscilloscope is an electronic device that is often used to measure and visualize a sound’s frequency. The frequency of a sound can be calculated by dividing the rate of the compressions and rarefactions by the length of a soundwave. It is called pitch in musical terminology, and is measured in hertz. It is measured in decibels in time (usually milliseconds), and is often visually represented and analyzed as a waveform.įrequency defines how high or low a sound is. In musical terms, envelope is often described as articulation. Amplitude is calculated in decibels, a logarithmic scale, and measured over time with a level meter.Įnvelope defines how the amplitude of a sound changes over time. In musical terms, it is often known as dynamics. These variables include:Īmplitude measures the volume of a sound. Many of the variables which contribute to a sound’s particular quality are measurable thanks to the work of scientists and mathematicians who have created systems that allow us to calculate sound in various ways. Determining and calculating these variables allow someone to understand the mathematics behind sound. But the variations in how such vibrations occur are nearly limitless, creating every sound imaginable, and all the world’s musical traditions. Scientifically speaking, sound is nothing more than the vibratory movement of air molecules. Students use mathematics to compare and contrast the amplitude, envelope, frequency, and spectrum of each of the four sounds, thereby coming to a better understanding of what physical phenomena contribute to an instrument’s unique sound. In this lesson, students examine the mathematics behind sound by identifying four mathematical variables that define the particular quality of a sound by closely analyzing the sound of four different musical instruments.

Background info about soundwaves