The evolutionary success of a species is linked to its ability to communicate. Auditory, optic and olfactory systems are biological communication channels. Compared to the latter two, auditory systems are less impeded by physical obstructions. Successful species have effectively articulated this to their advantage. Decoding the acoustic dynamics of a landscape can ingeniously be crafted as a rapid tool to assess biological diversity. Here, we present results of the acoustic analysis carried out in three contrasting soundscapes in Kerala, India. Representative sound samples were recorded at Ernakulam, Kerala, India using Marantz PMD 661 III sonic recorder from 6.00 a.m. to 6.00 p.m. (IST) from an urban park Hill Palace Museum (L1), a sacred grove Iringole Kavu (L2), and a legally protected area Salim Ali Bird Sanctuary (L3). Acoustic characteristics of these sites expressed as Acoustic Complexity Index (ACI), Acoustic Diversity Index (ADI), Acoustic Evenness Index (AEI), Bioacoustic Index (BI) and Normalized Difference Soundscape Index (NDSI) were related to corresponding avian diversity. The objective finding reveals the distinctiveness of sonic characteristics and the status of diversity in each soundscape. Rapid assessment of biodiversity using acoustic indices is a prospective option that can be adopted as a means to generate biodiversity indicators of Sustainable Develeopment Goals (SDGs).