Refining ecoacoustic indices in aquatic and terrestrial ecosystems: A comprehensive review and bibliometric analysis

In recent years, ecological acoustic assessment based on Passive Acoustic Monitoring technology has gained widespread attention as a non-invasive method, providing scientific evidence for biodiversity monitoring and wildlife conservation. Although this approach, as a newly established ecological research method, faces numerous challenges to prove its effectiveness, it has gradually established a comprehensive analytical process supported by numerous studies. This study analyzes the application of ecoacoustic indices in assessing terrestrial and underwater environments and biodiversity detection, identifying commonly used indices. After summarizing the principles of these ecoacoustic indices, the study highlights the suitable indices for different application environments and the influencing factors to consider. Additionally, a bibliometric analysis was conducted on related articles and their keywords retrieved from the Web of Science database, visualizing the relationships. Based on this, the study predicts the development trends of ecoacoustic indices and envisions their broader application in other fields. This research provides a clear overview of the use of ecoacoustic indices and offers theoretical references for the development of the field.