1. Noise Aperiodic complex wave
Sound with an instantaneous amplitude that varies in a random manner. 1

2. White noise/Broadband noise
White noise: Contains all possible frequencies
Broadband noise: Contains all frequencies within certain broad limits
Limits define the bandwidth of the noise
These frequencies have the same average intensity or pressure
Amplitude spectrum: Continuous and flat
Phase spectrum: Random 2

3. Quantifying intensity of broadband noise
Total power:
Sum of the intensity of all the sinusoids in the noise.
Spectrum level (No): Also called noise power per unit bandwidth
Average intensity measured in a band of noise 1 Hz wide 3