acoustic_complexity_index: Acoustic Complexity Index

In soundecology: Soundscape Ecology

Description

Acoustic Complexity Index (ACI) from Pieretti, et al. 2011. The ACI is based on the "observation that many biotic sounds, such as bird songs, are characterized by an intrinsic variability of intensities, while some types of human generated noise (such as car passing or airplane transit) present very constant intensity values" (Pieretti, et al. 2011).

The index was tested to the ACItot calculated using SoundscapeMeter v 1.0.14.05.2012, courtesy of A. Farina.

The results given are accumulative. Very long samples will return very large values for ACI. I recommend to divide by number of minutes to get a range of values easier to compare.

Usage

	acoustic_complexity(soundfile, min_freq = NA, max_freq = NA, j = 5, fft_w = 512)
	

Arguments

soundfile	an object of class Wave loaded with the function readWave of the tuneR package.
min_freq	miminum frequency to use when calculating the value, in Hertz. The default is NA.
max_freq	maximum frequency to use when calculating the value, in Hertz. The default is the maximum for the file.
j	the cluster size, in seconds.
fft_w	FFT window to use.

Value

Returns a list with three objects per channel

AciTotAll_left	the ACI total for the left channel
AciTotAll_right	the ACI total for the right channel
AciTotAll_left_bymin	the ACI total for the left channel divided by the number of minutes
AciTotAll_right_bymin	the ACI total for the right channel divided by the number of minutes
aci_fl_left_vals	values of ACI(fl) for the left channel
aci_fl_right_vals	values of ACI(fl) for the right channel
aci_left_matrix	Matrix of all values before calculating ACI(fl) for the left channel
aci_right_matrix	Matrix of all values before calculating ACI(fl) for the right channel

References

Pieretti, N., A. Farina, and D. Morri. 2011. A new methodology to infer the singing activity of an avian community: The Acoustic Complexity Index (ACI). Ecological Indicators 11: 868-873. doi: 10.1016/j.ecolind.2010.11.005

Examples

	data(tropicalsound)
	ACI <- acoustic_complexity(tropicalsound)
	print(ACI$AciTotAll_left)
	
	summary(ACI)
	

soundecology documentation built on May 2, 2019, 3:21 a.m.