AmplitudeTier

A Praat AmplitudeTier: sound pressure amplitude in Pascals as a function of time.

Arguments

.xptr

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

Value

An AmplitudeTier object.

Details

An AmplitudeTier stores amplitude as a sparse sequence of (time, value) points rather than a dense signal, with linear interpolation between points. It's the amplitude counterpart to an IntensityTier (which stores dB instead of Pa), and the two convert into each other. A common use is pulling amplitude at glottal pulse times (from a PointProcess) to compute shimmer.

Usage

tier <- amplitude_tier_create(0, 1)
tier <- amplitude_tier_from_point_process(point_process, sound)
tier <- intensity_tier_to_amplitude_tier(intensity_tier)

Query methods

• get_start_time(), get_end_time() - time domain in seconds

• get_number_of_points() - number of (time, value) points

• get_time_from_index(index) - time at a 1-based point index

• get_value_at_index(index) - amplitude at a 1-based point index (Pa)

• get_value_at_time(time) - interpolated amplitude at a time (Pa)

Modification

• add_point(time, value) - add a (time, value) point

• remove_point(index) - remove the point at a 1-based index

Conversion and export

• to_intensity_tier(threshold_db) - convert amplitude to an IntensityTier

• as_data_frame() - points as a data frame with time and amplitude_pa columns

• save(path) - write to file

See also

[amplitude_tier_create], [amplitude_tier_from_point_process], [intensity_tier_to_amplitude_tier]

Examples

tier <- amplitude_tier_create(0, 1)
tier$add_point(0.25, 0.5)
tier$add_point(0.75, 0.8)
tier$get_number_of_points()
#> [1] 2
tier$get_value_at_time(0.5)
#> [1] 0.65