## 3 Results  
This article focuses on the statistical analysis of the F0 frequency value of oesophageal speech, comparing it with the physiological speech of healthy people. The focus is on determining the temporary value of the F0 frequency, resulting from the segmentation of the analysed signal. This means that the F0 value was determined based on the processing of a speech signal segment that represents at least several cycles of vocal fold or pseudo-glottis work, in the case of oesophageal speech (ES). The speech signal segment is separated using a moving time window (called a frame), while the basic F0 frequency within the frame is constant. Therefore, an F0 frequency vector (pitch listing) is obtained, the length of which depends on the number of frames. The number of frames depends on the length of the spoken word. The duration of the spoken word for oesophageal speech (ES) is longer compared to the speech of healthy people, which depends on the level of the patient's rehabilitation, including the ability to swallow appropriate air resources. In the case of single words, the time of expression may differ less than in the case of full sentences. Figures 3 and 4 show the time waveform and spectrogram of the word \"pacza\" (\"a package\") of spoken by a man who had had laryngectomy surgery and a healthy man. The following spectogram settings were used:  
Figure 2: F0 frequencies of selected oesophageal speech words. There is a significant difference in the length of the spoken word. Moreover, for both words, a pitch contour is displayed. The information collected regarding the F0 frequency of each single word tested included:  
1. the mean value of the F0 frequencies contained in the pitch listing  
Figure 4: Time waveform and spectrogram of the word “a package”—healthy man. Figure 3: Time waveform and spectrogram of the word “a package”—laryngectomised man. Figure 8: Standard deviation value of the F0 frequencies contained in the pitch listing. Figure 7: Maximum value of the F0 frequency from the pitch listing. Figure 9: Median value of the F0 frequencies contained in the pitch listing. Figure 10 presents the average values of the fundamental frequency F0 without taking into account the division according to the studied words. The main criterion is the differences between oesophageal speech (ES) and the speech of healthy people. From the presented Figure 10, we conclude that the greatest differences can be observed for max. pitch F0. The difference is equal to 29.68, which, taking into account 124.22 Hz for healthy people and 94.54 Hz for laryngectomised people, constitutes 76.1% in the ratio of laryngectomised people to healthy people. The full set of values for the average fundamental frequency F0 for all the words tested is presented in Table 3.  
The research performed shows that the largest difference regarding max. pitch F0 occurs in the tested word \"egg\" and is 47.58 Hz, as shown in Figure 11 and Table 4. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multicolumn{5}{c}{**Average Values of Fundamental Frequency F0 for All Tested Words**} \\ \hline \multirow{2}{*}{**F0 Frequency**} & \multirow{2}{*}{**Healthy**} & \multirow{2}{*}{**Laryngeal**} & **Percentage Value in the Ratio of People** & **Frequency** \\  & & & **Folololololumn{1}{c}{**Hatiy of People**} & **Difference—Healthy** \\  & & & **Following Laryngectomy** & **and Laryngectomised** \\  & & & **to Healthy People [\%]** & **People** \\ \hline Mean pitch F0 [Hz] & 96.87 & 80.86 & 83.48 & 16.01 \\ Min. pitch F0 [Hz] & 79.87 & 64.70 & 81.00 & 15.17 \\ Max. pitch F0 [Hz] & 124.22 & 94.54 & 76.10 & 29.68 \\ Median F0 & 94.68 & 83.14 & 87.82 & 11.53 \\ Standard deviation F0 & 17.54 & 12.61 & 71.89 & 4.93 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Set of values for the average fundamental frequency F0 for all tested words. Figure 10: Average values of fundamental frequency F0 for all tested words.