My use in ecology and habitat evaluation
Ecoacoustics brought a new look at the relationship between the environment and sounds—how are they connected with surrounding landscape and vegetation parameters? Of course, sounds are only the product of various organisms such as birds, mammals, amphibians, insects or fish. And not only organisms; humans and their activities produce sounds. An important part is made of geophony—wind, storms or geological processes. All these sources are covered by ecoacoustics. Some ecologists and other experts do not find it useful to study acoustic signals in the environment. They understand using them for the identification of animals that produce them. However, to study the distribution or diversity of acoustic signals themselves does not make sense to them.
I think, first, we should research ecoacoustics and its use in ecology and habitat evaluation. Then we can decide whether this field has a future. Today, it is questionable to use acoustic indices as a proxy for species diversity. A recent study (Sugai et al. 2026) showed them to be not useful for biodiversity research. Maybe it is true; I do not think they should replace classic biodiversity assessment based on surveys of species living in the area. They should describe the composition and distribution of acoustic signals in the soundscape. Here, the potential is more in the evaluation of habitat quality and monitoring of the health of the environment.
First results of my research showed a different diurnal pattern of the Acoustic Complexity Index (ACI) in native and non-native forest vegetation. The index describes the richness of acoustic signals in the recording. Significantly higher values were in the habitat with native forest vegetation. So, we can tell something about the habitat. In this case, where the main part of the signals was made of the sounds of birds, they were missing or changed their vocal activity in the changed habitat. Mean hourly values tell us when acoustic diversity is the highest. Here, in the morning and then before sunset. Other indices give information about different aspects of the soundscape. For example, the Acoustic Diversity Index (ADI) informs us how sounds are distributed across frequencies. A higher value means acoustic signals cover more frequencies; the soundscape is more diverse. In my study, ADI hourly values were not significantly different between two habitats. So, sound frequencies were similarly covered in both types of forest vegetation.
Based on indices we can characterize the site. They can inform about the impact of vegetation changes. I think that the main role of acoustic indices is to characterize the soundscape quantitatively. They have limited use as a proxy for animal species diversity. On the other hand, they offer complementary data for the health evaluation of the habitat.
References
Sugai, L. S. M., Balantic, C., Clink, D. J., Ramesh, V., Kahl, S., Klinck, H., & Wood, C. M. (2026). Acoustic indices are not useful for biodiversity research. Methods in Ecology and Evolution, 00, 1–13. https://doi.org/10.1111/2041-210x.70285