# Exploring the Influence of Avian Vocal Presence on Appraisal of Urban Soundscapes
## 5 Conclusions  
In this paper, one pre-recorded acoustic environment, which typically occurs in contemporary urban areas, has been used to design five new recordings which have been enriched by different singing bird species, namely blackbird, blackcap, chaffinch, great tit, and robin. Bearing in mind all the aforementioned, we investigated all six recordings in objective and subjective terms. The objective acoustical differences in the studied environments are loudness and spectral distributions, while subjective psychological parameters are determined by examining the responses of the study participants using a specially designed questionnaire. The designed questionnaire relied on the semantic differential method implemented by defining attribute pairs of opposite meanings, where each pair described a sound characteristic for a particular acoustic environment. After a detailed analysis of the results attained from the semantic differential and direct participant feedback, it can be concluded that the perception of the acoustic environment improves somewhat significantly by adding different singing bird species. When taking into consideration all the obtained data, mainly the overall rating (i.e., a combination of the attribute pairs and direct responses), the best result was achieved for the recording with the added sound of chaffinch. From an acoustical point of view, each bird species has a distinct pattern in a higher frequency band (i.e., from 1 kHz to 8 kHz), which can be observed in the spectrograms. In addition, listeners assigned different ratings and provided different responses for each bird species. Therefore, it can be established that urban residents do have certain preferences regarding bird species, especially when we consider the calculation and correlation of objective acoustic parameters (loudness, sharpness, roughness, and fluctuation strength) with subjective questionnaire results. The results presented here offer valuable insights into human response in terms of enriched soundscapes and suggest several avenues for future research. We plan to continue our work of raising awareness regarding the problems of the decrease in biodiversity as a consequence of noise pollution, especially in urban areas. Since the study has shown that listeners favor and enjoy the enriched soundscapes, it can serve as a guideline and path to future work regarding the selection of singing bird species. Future work will be oriented towards creating more soundscapes with different bird species in order to obtain a more extensive \"ranking system\" of singing birds in terms of listeners' perception and overall pleasantness. Thus, we believe that in collaboration with scientists from other fields, this type of finding will have a great impact on the quality of life in urban areas. Conceptualization, M.S., A.P., H.S. and I.D. ; methodology, M.S. ; software, A.P. ; validation, M.S., H.S., I.D. and A.P. ; formal analysis, M.S. ; investigation, M.S. ; resources, M.S. ; data curation, M.S. ; writing--original draft preparation, M.S. ; writing--review and editing, H.S. and I.D. ; visualization, A.P. ; supervision, I.D. and H.S. All authors have read and agreed to the published version of the manuscript. **Funding:** This research received no external funding. **Institutional Review Board Statement:** This type of study does not require involvement from the University's Ethics Committee. The study has been granted exemption by the Ethics Committee of The Faculty of Electrical Engineering and Computing, University of Zagreb (protocol code 023-01/24-01/1, approved 30 October 2024). **Informed Consent Statement:** Informed consent for participation was obtained from all subjects involved in the study. **Data Availability Statement:** The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author. **Conflicts of Interest:** The authors declare no conflicts of interest. **Appendix A**  
**Table A1.