12.1.2.5-2 Background Noise

Background noise should not impair verbal communication between any two points in the main operating area.

Additional Information:
Verbal communications should be intelligible using normal or slightly raised voice levels. Figure 12.3 shows the voice levels needed for spoken communication over specified distances in the presence of different levels of background noise. Intelligibility of speech in noise is affected by the frequency spectra of the noise and of the speakers' voices and by the speakers' hearing sensitivity.

Figure_12.3

Figure 12.3 Voice level as a function of distance and ambient noise level.