ndsi: Normalized Difference Soundscape Index

In soundecology: Soundscape Ecology

Description

Normalized Difference Soundscape Index (NDSI) from REAL and Kasten, et al. 2012. The NDSI seeks to "estimate the level of anthropogenic disturbance on the soundscape by computing the ratio of human-generated (anthrophony) to biological (biophony) acoustic components found in field collected sound samples" (Kasten, et al. 2012).

Tested with Matlab code courtesy of S. Gage.

Usage

ndsi(soundfile, fft_w = 1024, anthro_min = 1000, anthro_max = 2000, 
	bio_min = 2000, bio_max = 11000)

Arguments

soundfile	an object of class Wave loaded with the function readWave of the tuneR package.
fft_w	FFT window size.
anthro_min	minimum value of the range of frequencies of the anthrophony.
anthro_max	maximum value of the range of frequencies of the anthrophony.
bio_min	minimum value of the range of frequencies of the biophony.
bio_max	maximum value of the range of frequencies of the biophony.

Details

The bin size is determined as the difference between anthro_max and anthro_min, by default 1000 Hz.

Value

Returns a list with one object per channel

ndsi_left	NDSI value for the left channel
ndsi_right	NDSI value for the right channel
biophony_left	value for the biophony for the left channel
anthrophony_left	value for the anthrophony for the left channel
biophony_right	value for the biophony for the right channel
anthrophony_right	value for the anthrophony for the right channel

References

Remote Environmental Assessment Laboratory. http://www.real.msu.edu

Kasten, Eric P., Stuart H. Gage, Jordan Fox, and Wooyeong Joo. 2012. The Remote Environmental Assessment Laboratory's Acoustic Library: An Archive for Studying Soundscape Ecology. Ecological Informatics 12: 50-67. doi: 10.1016/j.ecoinf.2012.08.001

Examples

	data(tropicalsound)
	NDSI <- ndsi(tropicalsound)
	print(NDSI$ndsi_left)
	
	summary(NDSI)
	

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