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The frequency spectrum of sound

Summary

Sound waves are compression waves in air that cannot be seen. Physicists and sound engineers use several different types of graphs and charts to represent sound waves. A waveform graph depicts pressure over time. A frequency spectrum breaks a complex wave down into its component frequencies and shows their relative amplitudes. A spectrogram chart depicts both frequency and loudness as a function of time. Sound waves can also be represented mathematically as a sum of sine waves using Fourier’s theorem. In this lesson you will use an interactive simulation and a spectrogram tool to explore sound waves and their representations.
The frequency spectrum

Student lesson materials


Investigation


Electronic resources