## 2 Materials and Methods
### Realization of the Experiment
In Figure 3, a comparison of the frequency spectra of white and pink noise is shown. The spectrum displayed corresponds with the average value of the real generated white and pink noise of one set of ten measurements in the source room. It is evident that significant differences occur at low and high frequencies. Frequencies above 5 kHz have not been addressed, as significant attenuation occurs in any building structure in these bands. From the figure below, the differences between theoretical and real frequency spectra of both types of noise are evident. These are brought about by the nature of noise source (the generator used had an equalizer available that was set in a way, that the noise generated matched the theoretical spectrum as closely as possible), linearity of the source, and the properties of the room (field diffusion). The character of the real frequency spectrum in individual sets of measurements was checked and kept within the minimum deviation values. In all activities, special attention was paid to low frequencies, as these are currently problematic in terms of assessing building-acoustic properties. At low frequencies, the implementation of building-acoustic measures is difficult, and the subjective effect on humans is often more significant than the effect at high frequencies. Three factors were chosen for the conduct of the experiment: frequency (factor A), excitation interval (factor B), and type of excitation noise (factor C). The factors were assessed equally in all experiments performed. 1. Factor A. When evaluating the test, the results were divided into three frequency intervals with the following ranges (F1, F2): Interval I (from 50 to 100 Hz), Interval II (from 125 to 500 Hz), and Interval III (from 630 to 1000 Hz)). The low level of factor A is always determined by the low limit F1 and the high level by the limit F2 of the respective frequency interval. In all activities, special attention was paid to low frequencies, as these are currently problematic in terms of assessing building-acoustic properties. At low frequencies, the implementation of building-acoustic measures is difficult, and the subjective effect on humans is often more significant than the effect at high frequencies. Based on authors' previous research, we focused on the frequency spectrum from 50 to 1000 Hz when evaluating the results of the experiment, despite the fact that the measurements were performed in the standard measuring range. The differences in the measured values at frequencies above 1000 Hz were below the significance limit. 2. Factor B. In the case of factor B, we considered the excitation interval in the range in which the lower middle value is 76 dB and the upper excitation interval with a mean value of 100 dB. This interval was divided into partial intervals. Pink and white noise were excited in the source room at six selected excitation intervals: 75-78, 80-83, 85-88, 90-93, 95-98 and 98-102 dB. All values measured at the corner  
Figure 3: Comparison of average levels of real frequency spectrum of white and pink noise. measuring points in the source room at a specific excitation setting are in the range of one interval (e.g., 75-78 dB). The measurements were performed in 1/3 octave bands so that it was possible to record temporally and spatially averaged measurements of sound pressure levels at several positions of the noise source. Sound pressure levels were recorded with 125 ms sampling. 3. Factor C had two levels: white noise and pink noise, see Figure 3.  
The basic quantities that evaluate the apparent sound reduction index R' (dB), which characterizes the ability of the partition structure to transmit acoustic power propagating through the air from the source to the receiving room, are given in the STN EN ISO 16283-1 standard.