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SASLab Manual


Spectrogram window : Tools > Calculate Acoustic Complexity Index


This command calculates the Acoustic Complexity Index (ACI) according to the paper https://doi.org/10.1016/j.ecolind.2010.11.005.



The option normalize (divide result by the number of temporal steps and frequency bins) will output a mean value rather than a sum.

The option apply magnitude threshold will exclude spectrogram magnitudes below the defined threshold. These two additional options (which are not included in the original paper) have been added in order to cope with some of the shortcomings of the ACI.

The option display ACI versus time will display the individual ACI values of each temporal step in a separate curve window. The ACI total value will be copied into the Windows clipboard.

Due to a number of various major shortcomings, we believe however that the ACI (as many other proposed eco-acoustic indices) is NOT suited for reliably quantifying animal biodiversity.

Avisoft Bioacoustics last modified on 17 September 2019