Real signals
The sine wave is not often encountered in real life. Acoustic signals are much more complex, containing a large number of different frequencies. These signals can be periodic, and non periodic, and their properties can vary over time, or be steady state.
We consequently use Fourier analysis for which complex signals are treated like the sum of sine waves. Hence, the electroacoustic systems presented in this lecture will be studied frequency by frequency. This is called a harmonic analysis.
