This final paper describes the spectral measurement of noise in a communication node. The physical foundations of noise as a phenomenon are given, the physiological effects of noise in terms of human health are described, and noise measurement techniques are described. Measurement problems are elaborated and instrumentation is described. The practical part of the paper includes examples of measurements on typical noise sources in an apartment and spectral measurements in 3 communication nodes (server rooms) at the Faculty. The concluding part comments on noise levels, spectra, and possible impact on human health.