Table A1.
Abbreviations and descriptions of the acoustic parameters with high factor loadings.
| Parameter | Factor | Description |
|---|---|---|
| pf mean, max, min (Hz) | F1 | Mean, maximum, and minimum of the frequencies with the highest amplitude across time segments (PF) |
| diff mean, max, min (Hz) | F1 | Mean, maximum, and minimum differences between F0 and PF |
| dfa1 mean, max, min (Hz) | F1 | Mean, maximum, and minimum frequency, frequency at which the amplitude distribution reaches the first quartile across all time segments (distribution of frequency amplitudes = dfa) |
| dfa2 min (Hz) | F1 | Minimum frequency at which the amplitude distribution reaches the second quartile |
| fp1 mean (HZ) | F1 | Mean frequency of the first global frequency peak |
| pf total max, min (Hz) | F1 | Frequency of the total maximum and the total minimum amplitude |
| f2 mean (Hz) | F2 | Mean frequency of the second global frequency peak |
| Range mean, max, min (Hz) | F2 | Difference between highest and lowest frequency within a segment, mean across time segments, maximum, minimum |
| dfa2 mean, max (Hz) | F2 | Mean and maximum frequency at which the amplitude distribution reaches the second quartile |
| dfa3 mean, max, min (Hz) | F2 | Mean, maximum, and minimum frequency at which the amplitude distribution reaches the second quartile |
| pf jump | F3 | Maximum differences between successive PFs |
| pf trend mean, max | F3 | Mean and maximum deviation between pf and linear trend |
| F0 mean, max, min (Hz) | F4 | Mean, maximum, and minimum fundamental frequency across tonal time segments |
| Tonality (%) | F5 | Percentage of tonal time segments |
| BWF1 (Hz) | F6 | Bandwidth of the first formant |
| amprat2 | F7 | Amplitude ratio between second harmonic and F0 |
| amprat3 | F7 | Amplitude ratio between third and first harmonic |
| HNR mean, max | F8 | Differences between highest and lowest frequency within a segment, mean across all time segments, maximum (1 = no noise) |
| Jitter mean, max | F9 | Mean and maximum cycle-to-cycle variations in the F0, across all time segments |
| dfa1 max location | F10 | Relative position of the maximum value of the first dfa1 (0 = beginning of the call and 1 = end of the call) [(1/duration) × location] |
| dfa2 max location | F10 | Relative position of the maximum value of the second dfa1 [(1/duration) × location] |
| Shimmer mean, max | F11 | Mean and maximum cycle-to-cycle variations in the amplitude, across all time segments |
| cs max location | F12 | Relative position of the maximum value of the correlation coefficient of successive time segments [(1/duration) × location] |
| pf minimum location | F12 | Relative position of the minimum value of the peak frequency [(1/duration) × location] |
| cs mean | F13 | Mean correlation coefficient of successive time segments |
Detailed descriptions were partly taken from Hammerschmidt and Jürgens (2007).