ndsi {soundecology} | R Documentation |
Normalized Difference Soundscape Index
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 |
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)