# Tests of the Influence of DAF (Delayed Auditory Feedback) on Changes in Speech Signal Parameters
## 4 Result and Discussion  
Articulation rate is a commonly used tool for studying speech disorders [28]. Speech tempo varies across languages. For adult Polish speakers, it averages at 2 syllables per second during slow speech and 4-5 syllables per second during faster conversations [29]. Both female and male participants demonstrated a decrease in speech tempo as the delay increased. The highest average speech tempo was observed under natural speech conditions (0 ms delay), while the lowest occurred at the maximum delay (360 ms). The women exhibited generally slower speech rates compared to the men across all delay conditions, which may suggest differences in adaptive strategies or sensitivity to DAF. The men showed less variability in speech tempo across the different delay conditions, indicating greater stability in coping with delayed auditory feedback. Speech tempo also varied depending on the complexity of the photographs being described, which could reflect their intricacy or the individual difficulty level the participants experienced in describing them. Notably, as the delay increased, the participants' creativity and the length of their utterances significantly declined. In the context of verbal creativity, the authors refer to the ability to produce words with a greater number of syllables, enhanced speech fluency, as well as the temporal characteristics and manner of speech production. The results presented in Figures 3 and 4 indicate that delayed auditory feedback effectively disrupts speech fluency, compelling the participants to adopt a slower and more controlled speaking style while simultaneously impacting their focus. The decrease in speech tempo at higher delays likely stems from the need for more precise control over speech to mitigate disruptions caused by delayed feedback. The experiment focused on analyzing the fundamental frequency (pitch) of vowels. For all vowels, a general trend was observed: the frequency of the fundamental pitch changed depending on the DAF delay. In the absence of delay (0 ms), the pitch was typically the highest, while increasing the delay caused a reduction in pitch frequency, suggesting that DAF affects voice stability control. Among the vowels analyzed, the vowel 'A' exhibited the highest fundamental frequency, while the vowel 'U' had the lowest. These results reflect articulation characteristics and reduced resonance. The vowel 'U' demonstrated the highest pitch stability regardless of the delay value, indicating that it is less susceptible to disruptions caused by DAF. The greatest pitch variability was observed for the vowel 'A,' showing significant fluctuations. The results for both groups of subjects are presented in Tables 2 and 3 below. The data indicate that the group of women tested was more affected by the delay compared to the men, which contrasts with the existing literature [7]. For accurate sound production, vowels should be articulated effortlessly and without strain on the larynx. The typical fundamental frequency range for men is 85-180 Hz, and 165-255 Hz for women. The results from the existing literature and several factors may account for this discrepancy, ranging from the limited sample size to possible differences in task design, stimulus characteristics, or even cultural and linguistic background of the participants. It is also possible that individual variability within the female group was higher, leading to greater sensitivity to the delay condition. Further research with a larger and more diverse sample would be necessary to clarify the underlying causes of this divergence. DAF-induced delays influence the pitch of the women, causing a reduction in frequency at higher delay values. At a delay of 360 ms, all vowels exhibited a decrease in pitch, which may indicate difficulties in maintaining controlled voice production under the maximum delay conditions. The 180 ms delay appeared to have the least impact on the pitch, suggesting it may represent a threshold value where the DAF effect on voice remains minimal.