Table 1.
Description of the acoustic parameters used in the analysis
| Abbreviation | Formulation | Detailed description |
|---|---|---|
| Duration [ms]* |
Duration |
Call duration measured within the adjusted start- and end thresholds |
| DFA2 mean [Hz]* |
Distribution of frequency amplitudes |
Frequency at which the distribution of frequencies reaches the second quartile of the total distribution, mean values across time segments |
| DFB1ch mean [Hz]* |
Modulation of the first dominant frequency band |
Mean deviation between 1st dominant frequency band and floating average curve |
| Range mean [Hz]* |
Frequency range |
Mean difference between the highest and the lowest frequency |
| PFtr mean [Hz]* |
Trend of the peak frequency |
Mean deviation between the peak frequency (PF) and the liner trend |
| Cs mean* |
Consistency of time segments |
Mean correlation coefficient of all successive time segments of the call |
| F0 mean [Hz]+ |
Fundamental frequency |
Mean fundamental frequency across all time segments in which a harmonic structure could be detected |
| Noise [%]+ |
Noisiness |
Percentage of time segments in which no harmonic or disturbed structure could be detected |
| Hnr1 + | Harmonic to noise ratio | Harmonic to noise ratio in the first third of the overall call frequency (1 = no noise) |
The general macro (*) as well as the manual tonal macro (+) of LMA 2012 was applied for parameter extraction.