Available features¶
Time domain features¶
In bioacoustics, sometimes several frequency bands are interesting to study at the same time and extract features. pypam allows so by passing a list of bands to analyze. Then, a features per “time window” and per frequency band is computed.
For features analysis, the second dimension is:
- bands: all the bands analyzed (just as an int)
extra coordinates (metadata):
- band_lowfreq: low limit of the frequency band
- band_highfreq: high limit of the frequency band
The available features now are:
| Feature name | Type | string |
|---|---|---|
| Acoustic Complexity Index (ACI) | acoustic index | aci |
| Bioacoustic Index (BI) | acoustic index | bi |
| Spectral Entropy of Shannon (SH) | acoustic index | sh |
| Temporal Entropy of Shannon (SH) | acoustic index | th |
| Normalized Difference Sound Index (NDSI) | acoustic index | th |
| Acoustic Evenness Index (AEI) | acoustic index | aei |
| Acoustic Diversity Index (ADI) | acoustic index | adi |
| Zero Crossing Rate (ZCR) | acoustic index | zcr |
| Acoustic Diversity Index (ADI) | acoustic index | adi |
| Root Mean Squared Value (rms) | temporal feature | rms |
| Sound Exposure Level (SEL) | temporal feature | sel |
| Dynamic Range | temporal feature | dynamic_range |
| Peak | temporal feature | peak |
| Root Mean Squared Value Envelope | temporal feature | rms_envelope |
| Spectrum Slope | temporal feature | spectrum_slope |
Frequency domain features¶
pypam allows to compute frequency-domain analysis (spectrum, spectrogram, third octave band levels…) per “time window”
For frequency domain analysis, a second dimension, frequency is added. This represents the central frequency of the frequency band
In case of spectrograms, a third dimension is added, time, representing the seconds of the spectrogram at that specific time window
The available features are:
- spectrogram
- Spectrum * power_spectrum * psd (power spectral density)
- Spectral Probability Density (SPD)
- octave bands