MDVP-33 Parameters & Their Implications
1) APQ - Amplitude Perturbation Quotient /%/ - Relative evaluation of the period-to-period variability of the peak-to-peak amplitude within the analyzed voice sample at smoothing of 11 periods. Voice break areas are excluded. The amplitude of the voice can vary for a number of reasons. Cycle-to-cycle irregularity of amplitude can be associated with the inability of the cords to support a periodic vibration with a defined period and with the presence of turbulent noise in the voice signal. Breathy and hoarse voices usually have an increased APQ.
2) ATRI - Amplitude Tremor Intensity Index /%/ - Average ratio of the amplitude of the most intense low-frequency amplitude modulating component (amplitude tremor) to the total amplitude of the analyzed voice signal. The algorithm for tremor analysis determines the strongest periodic frequency and amplitude modulation of the voice. Tremor has both frequency and amplitude components (i.e., the fundamental frequency may vary and/or the amplitude of the signal may vary in a periodic manner). Tremor frequency provides the rate of change with Fftr providing the rate of periodic tremor of the frequency and Fatr providing the rate of change of the amplitude.
3) DSH - Degree of sub-harmonic components /%/ - Estimated relative evaluation of sub-harmonic to Fo components in the voice sample. The degree of sub-harmonic components in normal voices should be equal to zero. It is expected to increase in voices where double or triple pitch periods replace the fundamental in certain segments over the analysis length. These effects are typical for diplophonic voices and voices with glottal fry. The experimental observation of patients with functional dysphonia or neurogenic voice disorders may show increased values of DSH.
4) DUV - Degree of Voiceless /%/ - Estimated relative evaluation of non-harmonic areas (where Fo cannot be detected) in the voice sample. DUV measures the ability of the voice to sustain uninterrupted voicing. The normative threshold is 0 because a normal voice, in the defined task of sustaining voicing, should not have any voiceless segments. In case of phonation with pauses (such as running speech, voice breaks, delayed start or earlier end of sustained phonation), DUV also evaluates the pauses before, after and/or between the voiced areas.
5) DVB - Degree of Voice Breaks /%/ - Ratio of the total length of areas representing voice breaks to the time of the complete voice sample. However, like DUV, it measures the ability of the voice to sustain uninterrupted voicing. The normative threshold is 0 because a normal voice, during the task of sustaining voice, should not have any voice break areas. In case of phonation with pauses (such as running speech, voice breaks, delayed start or earlier end of sustained phonation), DVB evaluates only the pauses between the voiced areas.
6) Aftr - Amplitude-Tremor Frequency /Hz/ - The frequency of the most intensive low-frequency amplitude-modulating component in the specified amplitude-tremor analysis range. If the corresponding ATRI value is below the specified threshold, the Fatr value is zero. The algorithm for tremor analysis determines the strongest periodic frequency and amplitude modulation of the voice. Tremor has both frequency and amplitude components (i.e., the fundamental frequency may vary and/or the amplitude of the signal may vary in a periodic manner). Tremor frequency provides the rate of change with Fftr providing the rate of periodic tremor of the frequency and Fatr providing the rate of change of the amplitude. The program will determine the Fftr and Fatr of any signal if the magnitude of these tremors is above a low threshold of detection. Therefore, the magnitude of the frequency tremor (FTRI) and the magnitude of the amplitude tremor (ATRI) are more significant than the respective frequencies of the tremor.
7) Fftr - Fo-Tremor Frequency /Hz/ - The frequency of the most intensive low-frequency Fo-modulating component in the specified Fo-tremor analysis range. If the corresponding FTRI value is below the specified threshold, the Fftr-value is zero. The algorithm for tremor analysis determines the strongest periodic frequency and amplitude modulation of the voice. Tremor has both frequency and amplitude components (i.e., the fundamental frequency may vary and/or the amplitude of the signal may vary in a periodic manner). Tremor frequency provides the rate of change with Fftr providing the rate of periodic tremor of the frequency and Fatr providing the rate of change of the amplitude. The program will determine the Fftr and Fatr of any signal if the magnitude of these tremors is above a low threshold of detection. Therefore, the magnitude of the frequency tremor (FTRI) and the magnitude of the amplitude tremor (ATRI) are more significant than the respective frequencies of the tremor.
8) Fhi - Highest Fundamental Frequency /Hz/ - The greatest of all extracted period-to-period fundamental frequency values. Voice break areas are excluded. The pitch extraction range is defined to either search for periods from 70-625 Hz or 200-1000 Hz. Therefore, the “normal” range will not determine a fundamental over 625 Hz.
9) Flo - Lowest Fundamental Frequency /Hz/- The lowest of all extracted period-to-period fundamental frequency values. Voice break areas are excluded. The lowest fundamental within the defined period is extracted and displayed as Flo. However, the pitch extraction range is defined to either search for periods from 70-625 Hz or 200-1000 Hz. Therefore, the “high” range will not determine a fundamental under 200 Hz.
10) Fo - Average Fundamental Frequency /Hz/- Average value of all extracted period-to-period fundamental frequency values. Voice break areas are excluded.
11) FTRI - Frequency Tremor Intensity Index /%/ - Average ratio of the frequency magnitude of the most intensive low-frequency modulating component (Fo-tremor) to the total frequency magnitude of the analyzed voice signal.
12) Jita - Absolute Jitter /usec/ - An evaluation of the period-to-period variability of the pitch period within the analyzed voice sample. Voice break areas are excluded. The pitch of the voice can vary for a number of reasons. Cycle-to-cycle irregularity can be associated with the inability of the vocal cords to support a periodic vibration for a defined period. Usually this type of variation is random. They are typically associated with hoarse voices.
13) Jitt - Jitter Percent /%/ - Relative evaluation of the period-to-period (very short-term) variability of the pitch within the analyzed voice sample. Voice break areas are excluded. The pitch of the voice can vary for a number of reasons. Cycle-to-cycle irregularity can be associated with the inability of the vocal cords to support a periodic vibration for a defined period. Usually these types of variations are random. They are typically associated with hoarse voices.
14) NHR - Noise-to-Harmonic Ratio - Average ratio of the inharmonic spectral energy in the frequency range 1500-4500 Hz to the harmonic spectral energy in the frequency range 70-4500 Hz. This is a general evaluation of noise present in the analyzed signal. Increased values of NHR are interpreted as increased spectral noise which can be due to amplitude and frequency variations (i.e., shimmer and jitter), turbulent noise, sub-harmonic components and/or voice breaks.
15) NSH - Number of Sub-Harmonic Segments - Number of autocorrelation segments where the pitch was found to be a sub-harmonic of Fo. The number of sub-harmonic components in normal voices should be equal to zero. It is expected to increase in voices where double or triple pitch period replaces the fundamental in certain segments over the analysis length. These effects are typical for diplophonic voices and voices with glottal fry. The experimental observation of patients with functional dysphonia or neurogenic voice disorders show increased values of DSH.
16) NUV - Number of Unvoiced Segments - Detected during the autocorrelation analysis. NUV measures the ability of the voice to sustain uninterrupted voicing. The normative threshold is 0 because a normal voice, in the defined task of sustaining voicing, should not have any voiceless segments. In case of phonation with pauses (such as running speech, voice breaks, delayed start or earlier end of sustained phonation) NUV evaluates also the pauses before, after and/or between the voiced areas.
17) NVB - Number of Voice Breaks - Number of times the fundamental period was interrupted during the voice sample (measured from the first detected period to the last period). NVB does not reflect the pauses before the first and after the last voiced areas of the recording. However, like NUV, it measures the ability of the voice to sustain uninterrupted voicing. The normative threshold is 0 because a normal voice, during the task of sustaining voice, should not have any voice break areas. In case of phonation with pauses (such as running speech, voice breaks, delayed start or earlier end of sustained phonation), NVB evaluates only the pauses between the voiced areas.
18) PER - Number of Pitch Periods - Detected during the voice sample.
19) PFR - Phonatory Fundamental Frequency Range
20) PPQ - Pitch Period Perturbation Quotient /%/ - Relative evaluation of the period-to-period variability of the pitch within the analyzed voice sample with a smoothing factor of 5 periods. Voice break areas are excluded. Cycle-to-cycle irregularity can be associated with the inability of the vocal folds to support a periodic vibration with a defined period. Hoarse and/or breathy voices may have an increased PPQ.
21) RAP - Relative Average Perturbation /%/ - Relative evaluation of the period-to-period variability of the pitch within the analyzed voice sample with smoothing factor of 3 periods. Voice break areas are excluded. Cycle-to-cycle irregularity can be associated with the inability of the vocal cords to support a periodic vibration with a defined period. Hoarse and/or breathy voices may have an increased RAP.
22) sAPQ - Smoothed Amplitude Perturbation Quotient /%/ - Relative evaluation of the short- or long-term variability of the peak-to-peak amplitude within the analyzed voice sample at smoothing factor defined by the user. The factory setup for the smoothing factor is 55 periods (providing relatively long- term variability; the user can change this value as desired). Voice break areas are excluded. They are typical for hoarse and breathy voices.
23) SEG - Total number of Segments - Computed during the autocorrelation analysis.
24) ShdB - Shimmer in dB /dB/ - Evaluation in dB of the period-to-period (very short-term) variability of the peak-to-peak amplitude within the analyzed voice sample. Voice break areas are excluded. Cycle-to-cycle irregularity of amplitude can be associated with the inability of the vocal folds to support a periodic vibration for a defined period and with the presence of turbulent noise in the voice signal. Usually, this type of variation is random. It is typically associated with hoarse and breathy voices.
25) Shim - Shimmer Percent /%/ - Relative evaluation of the period-to-period (very short term) variability of the peak-to-peak amplitude within the analyzed voice sample. Voice break areas are excluded. Cycle-to-cycle irregularity of amplitude can be associated with the inability of the cords to support a periodic vibration for a defined period and with the presence of turbulence noise in the voice signal. Usually this type of variation is random. They are typically associated with hoarse and breathy voices.
26) SPI - Soft Phonation Index - Average ratio of the lower-frequency harmonic energy in the range 70-1600 Hz to the higher-frequency harmonic energy in the range 1600-4500 Hz. SPI can be thought of as an indicator of how completely or tightly the vocal folds adduct during phonation. Increased value of Soft Phonation Index is generally an indication of loosely or incompletely adducted vocal folds during phonation. However, it is not necessarily an indication of a voice disorder. Similarly, patients with “pressed” phonation may likely have a “normal” SPI though their pressed voice characteristic may not be desirable. Therefore, a high SPI value is not necessarily bad, nor a low SPI value necessarily good. The parameter is, however, very useful for studying how strongly the vocal folds adduct and whether they adduct completely.
27) sPQ - Smoothed Pitch Period Perturbation Quotient /%/ - Relative evaluation of the short or long-term variability of the pitch period within the analyzed voice sample at smoothing factor defined by the user. The factory setup for the smoothing factor is 55 periods. Voice break areas are excluded. It is typical for hoarse voices.
28) STD - Standard Deviation of the Fundamental Frequency /Hz/- Standard deviation of all extracted using the VOICE command period-to-period fundamental frequency values. Voice break areas are excluded.
29) To - Average Pitch Period /msec/- Average value of all extracted using the VOICE command pitch period values. Voice break areas are excluded.
30) Tsam - Length of Analyzed Voice Data Sample /sec/.
31) vAm - Coefficient of Amplitude Variation /%/ - Relative standard deviation of the peak-to-peak amplitude. It reflects in general the peak-to-peak amplitude variations (short to long-term) within the analyzed voice sample. Voice break areas are excluded.
32) vFo - Coefficient of Fundamental Frequency Variation /%/ - Relative standard deviation of the fundamental frequency. It reflects, in general, the variation of Fo (short to long-term) within the analyzed voice sample. Voice break areas are excluded.
33) VTI - Voice Turbulence Index - Average ratio of the spectral inharmonic high-frequency energy in the range 2800-5800 Hz to the spectral harmonic energy in the range 70-4500 Hz in areas of the signal where the influence of the frequency and amplitude variations, voice breaks and sub-harmonic components are minimal. VTI measures the relative energy level of high-frequency noise. VTI mostly correlates with the turbulence caused by incomplete or loose adduction of the vocal folds. VTI, unlike NHR, analyzes high frequency components to extract an acoustic correlate to “breathiness”.
KUNNAMPALLIL GEJO
Thanks! :D
ReplyDeleteThanks a lot. Kind of helped me with my healthcare analytics assignment
ReplyDelete