Class AcousticComplexityIndex

Inheritance

Object

AcousticComplexityIndex

Inherited Members

Object.Equals(Object)

Object.Equals(Object, Object)

Object.GetHashCode()

Object.GetType()

Object.MemberwiseClone()

Object.ReferenceEquals(Object, Object)

Object.ToString()

Namespace: AudioAnalysisTools

Assembly: AudioAnalysisTools.dll

Syntax

public static class AcousticComplexityIndex

Methods

CalculateAci(Double[,])

Returns an array of ACOUSTIC COMPLEXITY INDICES This implements the index of N. Pieretti, A. Farina, D. Morri. in "A new methodology to infer the singing activity of an avian community: The Acoustic Complexity Index (ACI)" in Ecological Indicators 11 (2011) pp868–873.

Declaration

public static double[] CalculateAci(double[, ] spectrogram)

Parameters

Type	Name	Description
Double[,]	spectrogram	this is an AMPLITUDE spectrum. All its values are positive.

Returns

Type	Description
Double[]	array of ACI values.

SumOfAmplitudeDifferences(Double[,])

Returns an array of DIFFERENCE values used in top line of calculation of ACOUSTIC COMPLEXITY INDICES See the above method. NOTE: There is one less difference than the number of elements in the freq bin. When ACI is subsequently calculated, the SUM of freq bin values will be over all values but the sum of DIFFERENCES will be over one less value. WHen ACI is calculated over a long interval i.e. one minute this is not a problem. When calculated over 0.2s, need to compensate. To get an almost correct approx to the ACI value calculated over a long interval, we add the average DIF to the total DIFF. So the number of difference values equals the number of freq bin values, when it comes to calculate ACI = DIFF / SUM This problem arises because of the very short segment duration e.g. 0.2 s segment = 8-9 frames.

Declaration

public static double[] SumOfAmplitudeDifferences(double[, ] spectrogram)

Parameters

Type	Name	Description
Double[,]	spectrogram	this is an amplitude spectrum.

Returns

Type	Description
Double[]	an array of DIFFERENCE values.