What is Sound Spectrum?

Sound Spectrum is a representation of sound in frequency domain.

It is displayed at the bottom of "Noise Exposure Meter" window. Y-axis is amplitude in decibel (dB), whereas x-axis is frequency from 20Hz to 20KHz.

If user whistles, user will see a spike-shaped spectrum. The "spike" is centered around the frequency of user pitch. On the contrary, a white noise will show a flat shape across frequencies.

In general, sound Spectrum shows how energy is allocated onto each frequency.