## 1 Introduction
Polish speakers had the highest mean F0, significantly higher than the lowest mean F0 found among German speakers. Their research implies stereotypes about speaker voice quality in different linguistic communities: Italian speakers are often perceived as having \"rougher\" voices, while Polish speakers are considered to have \"clearer\" voices. More specifically, concerning the perception aspects, the loss of the speech spectrum below 350 Hz in the Polish language results in only a 2% reduction in speech clarity. Thus, low-frequency sounds in speech appear to have minimal significance. The frequent occurrence of sibilants and consonant clusters in Polish, which utilize the higher frequency range, suggests that comprehensible speech can be estimated at 85% clarity within the 1 kHz-5 kHz range. Consequently, extensive exposure to speech frequencies within the 400 Hz-4000 Hz spectrum, necessary for understanding Polish, does not provide the listener with adequate sensitivity to bass and treble sounds ([36]: pp. 104-105). High-pass and low-pass filtering applied to the Polish language reveals the importance of a specific frequency range, shown in Table 1. We can assume that the pitch accent in Polish over a syllable, a word (a lexical stress) or a phrase (an intonational stress), represented by the fundamental frequency in a certain range of register, is still distant (i.e., higher) from the F0 exploited in tonal phonemes (also known as tonemes) in modern Mandarin Chinese. Regarding the study of tonal production by Polish learners of Mandarin, ref. [7] asked a phonetician and 15 native speakers of Taiwanese Mandarin to evaluate recordings made by 10 Polish students (4 M and 6 F). The results indicated that the learners' production of T3 had a longer rising part, which evaluators often perceived as T2. Conversely, T2, which starts with a slight dip followed by a rise, was often mistaken for T3. Ref. [39] used 108 phrases (17 monosyllabic words and 91 disyllabic words) and compared the production of 26 Polish learners of Mandarin (10 M and 16 F) with that of 10 Taiwanese Mandarin speakers. Two native Mandarin speakers with professional phonetic training evaluated the production using a five-point scale. Additionally, z-score analysis was conducted on 11 evenly spaced points, with the latter six points used as the basis for the study. The \begin{table}
\begin{tabular}{c c} \hline \hline  & **Mandarin Chinese** & **Polish** \\ \hline [PERSON], 1981 [32] & 45 Hz to 250 Hz (female) \\ \hline [PERSON], 2005 [34] & 104 Hz to 262 HZ (female) \\ \hline [PERSON], 1986 [8] & 162 Hz to 352 Hz (female) \\ \hline [PERSON], 1976 [33] & 40 Hz to 157 Hz (male) \\ \hline [PERSON], 2005 [34] & 78 to 185 HZ (male) \\ \hline [PERSON], 1986 [8] & 68 Hz to 223 Hz (male) \\ \hline [PERSON], 1997 [31] & 90 Hz to 140 Hz (male) \\ \hline [PERSON] and [PERSON], 2005 [36] & 1300–1600 HZ \\  & 100–2300 HZ (significant) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Comparisons of the tonal ranges in Mandarin Chinese and Polish. study found that Polish learners, who received scores of 4-5 for their tonal performance, had overall mean values and tonal slopes closer to those of Taiwanese Mandarin speakers. Although there was a significant difference in the mean values for disyllabic words starting with T3, this difference was smaller than that for Polish participants, who received scores of 1-2. Furthermore, Polish participants who received scores of 1-3 had mean values and tonal slopes significantly different from those of Taiwanese Mandarin speakers, particularly for disyllabic words starting with T1 (too low) and T3 (too high). Errors in tonal contour primarily occurred in disyllabic words starting with T2 (similar to T1) and T4 (similar to T2). Overall, the tonal range (tonal register) of Polish learners was narrower than that of Taiwanese speakers. The main difficulty for the learners was establishing the concept of pitch variation at the syllabic level. Ref.