| Sound and Noise |
| A simple definition for noise might be, that noise is unwanted sound. There are different kinds of sounds and noise. A pure sine tone consists of a single frequency. Tones from e.g. music instruments might consist of a mixture of different frequencies, typically the basic frequency and some harmonic frequencies with multiple frequency values of the basic tone. Other kinds of sounds are a mixture of many frequencies in a given frequency range and we call this for broad band noise. Special broad band noises are used for measurements in acoustics, the “white noise” and the “pink noise”. Both types have more or less all frequencies within the specifi ed range (e.g. 50 Hz to 10000 Hz), the difference is the energy at each frequency.  |
