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Praat PointProcess object

Source: R/pointprocess-wrapper.R
PointProcess.Rd

A PointProcess is a sequence of time points, typically representing glottal pulse boundaries (moments of vocal fold closure). Used for voice quality analysis: jitter (period perturbation) and shimmer (amplitude perturbation).

Arguments

tmin, tmax

When creating an empty PointProcess, the time span of the object. Leave NULL (the default) when supplying .xptr.

.xptr

Not for direct use. External pointer to the underlying C++ PointProcess object; set internally when a method returns a new PointProcess.

Value

A PointProcess object with methods for glottal pulse analysis, including jitter and shimmer.

Query methods

  • get_number_of_points() - total number of time points

  • get_time(index) - time of point at index

  • get_nearest_index(time) - index of point nearest to a given time

  • get_low_index(time), get_high_index(time) - index bounding a time

  • get_interval(time) - time between surrounding points

  • get_mean_period(from_time, to_time, ...) - mean glottal period

  • get_stdev_period(from_time, to_time, ...) - SD of glottal period

  • get_number_of_periods(from_time, to_time, ...) - number of periods in range

  • get_voice_breaks(from_time, to_time, ...) - number of voice breaks

Jitter methods

Period perturbation measures. See the Note section for units.

  • get_jitter_local(from_time, to_time, ...) - local jitter (Jloc)

  • get_jitter_local_absolute(from_time, to_time, ...) - local absolute jitter

  • get_jitter_rap(from_time, to_time, ...) - relative average perturbation

  • get_jitter_ppq5(from_time, to_time, ...) - 5-period perturbation quotient

  • get_jitter_ddp(from_time, to_time, ...) - difference of differences of periods

Shimmer methods

Amplitude perturbation measures; each takes a Sound. See the Note section for units.

  • get_shimmer_local(sound, from_time, to_time, ...) - local shimmer (Shim)

  • get_shimmer_local_db(sound, from_time, to_time, ...) - local shimmer in dB

  • get_shimmer_apq3(sound, from_time, to_time, ...) - 3-period amplitude perturbation quotient

  • get_shimmer_apq5(sound, from_time, to_time, ...) - 5-period APQ

  • get_shimmer_apq11(sound, from_time, to_time, ...) - 11-period APQ

  • get_shimmer_dda(sound, from_time, to_time, ...) - difference of differences of amplitude

Batch and report methods

  • get_jitter_shimmer_batch(pointprocess, sound, ...) - all jitter and shimmer values as a named list, computed in one C++ call. Cache-aware: later calls with the same parameters return instantly.

  • voice_report(sound, pitch, ...) - combined voice report (jitter, shimmer, HNR)

Export and conversion methods

  • as_vector(), as_data_frame() - export as a vector or data.frame

  • to_textgrid_vuv(max_voiced_period, ...) - create a voiced/unvoiced TextGrid

  • to_pitch_tier() - convert to a PitchTier

  • to_sound_pulse_train(...) - create a pulse train Sound

Note

Jitter and shimmer values are returned as decimals (0-1), not percentages. Multiply by 100 for percentage display. The first shimmer call caches all 11 metrics; later jitter or shimmer calls with matching parameters return from cache (no additional C++ call).

See also

Sound, Pitch, AmplitudeTier

Examples

sound <- Sound$create_tone(duration = 1.0, frequency = 150, sampling_rate =
 44100)
pp <- sound$to_point_process_periodic_cc(pitch_floor = 75, pitch_ceiling =
 600)
jitter <- pp$get_jitter_local()
shimmer <- pp$get_shimmer_local(sound)