Often the sound energy from a noise source will be spread over a wide band of frequencies. Sometimes a noise source will emit noise that is concentrated in a narrow part of the spectrum or contains a high proportion of energy at a single frequency (a âpure toneâ). This is referred to as tonal noise.
Tonal Noise Analysis with Optimus Green Sound Level Meters
![](https://www.cirrusresearch.co.uk/blog/wp-content/uploads/2012/03/optimus-sound-level-meterx825x350.jpg)