Bioacoustic Field Calculators
Standardized ecological acoustic metrics based on Pieretti et al. (2011) & Kasten et al. (2012).
Normalized Difference Soundscape Index (NDSI)
NDSI estimates the ratio between biophony (bird vocalizations: 2–8 kHz) and anthrophony (human traffic/machinery: 1–2 kHz).
Biophony Energy (2–8 kHz)75%
Anthrophony Energy (1–2 kHz)25%
Evaluated NDSI
+0.5
Moderate Biophony
Good biological signal. Moderate background wind or distant traffic detectable.
Acoustic Complexity Index (ACI) Calculator
Computes the absolute difference in spectral intensity between consecutive temporal bins. Constant anthropogenic noise has ACI near 0; diverse bird songs generate high ACI.