Trane TRG-TRC007-EN manual Broadband Sound and Tones, Fundamentals of Sound, period one

period one

Fundamentals of Sound

notes

Broadband Sound
amplitude
time	Figure 6

The wave form shown in Figure 5 represents sound occurring at a single frequency. This is called a pure tone.

A pure sinusoidal wave form, however, is very rare in HVAC acoustics. Typically, sounds are of a broadband nature, meaning that the sound is composed of several frequencies and amplitudes, all generated at the same time. Figure 6 represents the components of broadband sound.

Broadband Sound and Tones

tone

amplitude

frequency	logarithmic scale
	Figure 7

Alternatively, plotting the amplitude (vertical axis) of each sound wave at each frequency (horizontal axis) results in a graphic of the broadband sound that looks like this. As you can see from this example, the sound energy is greater at some frequencies than at others.

TRG-TRC007-EN 5