| Jitter(%) |
Average absolute difference between consecutive periods, divided by the average period. |
| Jitter(Abs) |
Average absolute difference between consecutive periods which gives information about the cycle-to-cycle variation of fundamental frequency given in seconds. |
| Jitter:RAP |
Relative Average Perturbation (RAP), which is the average absolute difference between a period and the average of it and its two neighbours, divided by the average period. |
| Jitter:PPQ5 |
Five-point Period Perturbation Quotient, computed as the average absolute difference between a period and the average of it and its four closest neighbours, divided by the average period. |
| Jitter:DDP |
Average absolute difference between consecutive differences between consecutive periods, divided by the average period. |
| Shimmer |
Average absolute difference between the amplitudes of consecutive periods, divided by the average amplitude. |
| Shimmer(dB) |
Average absolute base-10 logarithm of the difference between the amplitudes of consecutive periods, multiplied by 20. It gives information about the variability of the peak-to-peak amplitude in decibels. |
| Shimmer:APQ3 |
Three-point Amplitude Perturbation Quotient, the average absolute difference between the amplitude of a period and the average of the amplitudes of its neighbours, divided by the average amplitude. |
| Shimmer:APQ5 |
Five-point Amplitude Perturbation Quotient, the average absolute difference between the amplitude of a period and the average of the amplitudes of it and its four closest neighbours, divided by the average amplitude. |
| Shimmer:APQ11 |
11-point Amplitude Perturbation Quotient, the average absolute difference between the amplitude of a period and the average of the amplitudes of it and its ten closest neighbours, divided by the average amplitude. |
| Shimmer:DDA |
Average absolute difference between consecutive differences between the amplitudes of consecutive periods. |
| Noise to Harmonics Ratio (NHR) |
Amplitude of noise relative to tonal components. It quantifies the noise which occurs due to turbulent airflow, resulting from incomplete vocal fold closure in speech pathologies. |
| Harmonics to Noise Ratio |
Amplitude of tonal relative to noise components. It has the same aim as NHR. |
| Recurrence period density entropy |
Addresses the ability of the vocal folds to sustain stable vocal fold vibrations, quantifying the deviations from exact periodicity |
| Detrended fluctuation analysis |
Quantifies the self-similarity of the noise present in the speech caused by the turbulent air flow |
| Pitch period entropy |
Measures the impaired control of stable pitch during sustained phonations |
