# Tests of the Influence of DAF (Delayed Auditory Feedback) on Changes in Speech Signal Parameters
## 5 Conclusions  
The effect of auditory feedback is one of the phenomena that impacts healthy individuals by introducing speech disruptions. However, the ambiguity of the currently available findings prompted the authors to explore this topic further [7]. Auditory feedback significantly affects speech fluency and production, making it a crucial tool in working with individuals who have severe speech disorders as well as those capable of fluent speech (without disfluencies). In summarizing the collected data, it can be concluded that DAF influences healthy individuals by slowing their speech and requiring greater focus when articulating subsequent words. The authors paid special attention to the results of multiple parameters, as they highlighted the participants' susceptibility to delays. Observations suggest that the DAF effect significantly impacts the speech tempo and reading time, which could be relevant for speech therapy aimed at improving the articulation of both healthy individuals and those with disfluencies. This paper introduces a novelty by applying DAF in healthy individuals with specific speech parameters. The proposed approach improves the understanding of speech pathologies and may contribute to more effective therapeutic interventions within the target research field. To expand the research on Delayed Auditory Feedback in the future, it would be beneficial to include a larger group of participants. With the support of speech therapists, extending the study to include younger individuals should be considered. To develop therapy for individuals with disfluencies based on the phenomenon of DAF, it would be valuable to also examine individuals at risk of or already affected by stuttering, Parkinson's disease, or Alzheimer's disease [32,33]. It is worth considering expanding the research to include physical parameters such as rapid movements of the face or skin during the examination. It is also worth checking whether these movements, e.g., rapid changes in facial expression, can be correlated or used to study this type of pathology together with DAF parameters. During the course of the study, certain limitations were identified, including the characteristics of the sample, methodological constraints, measurement precision, and the size of the study group. It would be advisable to address these issues in future research to further improve the methodological approach. In the future, a more precise investigation of jitter and shimmer parameters using advanced software would be desirable. Additionally, to better understand the impact of the DAF phenomenon on reading, selecting materials with a balanced number of syllables and a broad range of readability indices would help assess how text complexity affects participants. Conceptualization, P.S. ; methodology, D.K. ; validation, P.S. and D.K. ; formal analysis, D.K. ; investigation, D.K. ; resources, D.K. ; writing--original draft preparation, D.K. ; writing--review and editing, P.S. ; visualization, D.K. All authors have read and agreed to the published version of the manuscript. This research received no external funding. **Institutional Review Board Statement:** The regulations of the Ethics Committee at Wroclaw University of Science and Technology provide for the review of research projects \"involving human participants,\" although they do not precisely define the notion of participation. Instead, they indicate categories of participants for whom obtaining approval is required. This list is not exhaustive but exemplary (\"in particular\"), highlighting typical groups of research participants for whom a higher level of care and caution is recommended. At the same time, the regulations limit the review process to projects classified as \"non-invasive empirical research,\" meaning research that \"does not interfere with the participant's body\" [34]. The internal regulations of universities must comply with national legislation; therefore, they are fully consistent with the legal framework in force in Poland.