Is monitoring biodiversity with acoustic indices a cul-de-sac?

The prevalent use of ecoacoustic indices as biodiversity proxies for large scale monitoring is facing growing scrutiny. In this study conducted across seven terrestrial habitats, we highlight the need for a more nuanced approach. While traditional indices often fail to correlate with species richness, we demonstrate that new indices have robust and universal predictive capabilities for terrestrial habitats. Additionally, we emphasize the importance of rigorous sampling protocols and the use of appropriate regression methods to ensure reliable and generalizable results. By addressing these methodological considerations, we posit that passive acoustic monitoring can still provide valuable insights into biodiversity assessment and contribute to the development of Essential Biodiversity Variables.