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Formant estimation using the Praat burg algorithm implementation

praat_formant_burg.Rd

Formants are estimated using Praat's built in function (burg algorithm). The function also computes the intensity (L) of the formant based on the power of the spectrum at the frequency of the formant. Naturally, if the algorithm failed to find a formant in a specified time frame, then the function will not return a formant frequency, bandwidth and intensity estimation.

Usage

praat_formant_burg(
  listOfFiles,
  beginTime = 0,
  endTime = 0,
  windowShift = 5,
  numFormants = 5,
  maxFormantHz = 5500,
  windowSize = 30,
  preemphasis = 50,
  trackFormants = TRUE,
  numberOfTracks = 3,
  nominalF1 = 550,
  nominalF2 = 1650,
  nominalF3 = 2750,
  frequencyCost = 1,
  bandwidthCost = 1,
  transitionCost = 1,
  windowShape = "Gaussian1",
  relativeWidth = 1,
  spectWindowShape = "Gaussian",
  spectResolution = 40,
  toFile = TRUE,
  explicitExt = "pfm",
  outputDirectory = NULL,
  verbose = FALSE,
  praat_path = NULL
)

Arguments

listOfFiles

a vector of wav file paths to be processed by function.

beginTime

the time where processing should end (in s) The default is 0 (zero) which means that the computation of formants will start at the start of the sound file.

endTime

the time where processing should end (in s) The default is 0 (zero) which means that formants will be computed up to the end of the file.

windowShift

the analysis window shift length (in ms).

numFormants

the number of formants that the analysis should try to find

windowSize

the analysis window length (in ms).

preemphasis

the frequency from which a preemphasis will be applied.

trackFormants

boolean; Should Praat attempt to gather short time formant frequency estimates into tracks?

numberOfTracks

The number of tracks to follow (if trackFormants is TRUE), and the number of tracks in the output. Information on frequencies bandwidths of formants with numbers above numberOfTracks will be discarded.

nominalF1

Described by the Praat manual as the preferred value near which the first track wants to be. For average (i.e. adult female) speakers, this value will be around the average F1 for vowels of female speakers, i.e. 550 Hz.

nominalF2

Described by the Praat manual as the preferred value near which the second track wants to be. A good value will be around the average F2 for vowels of female speakers, i.e. 1650 Hz.

nominalF3

Described by the Praat manual as the preferred value near which the third track wants to be. A good value will be around the average F3 for vowels of female speakers, i.e. 2750 Hz. This argument will be ignored if you choose to have fewer than three tracks, i.e., if you are only interested in F1 and F2.

frequencyCost

Described by the Praat manual as the preferred value near which the five track wants to be. In the unlikely case that you want five tracks, a good value may be around 4950 Hz.Frequency cost (per kiloHertz)

bandwidthCost

Described by the Praat manual as the local cost of having a bandwidth, relative to the formant frequency. For instance, if a candidate has a formant frequency of 400 Hz and a bandwidth of 80 Hz, and Bandwidth cost is 1.0, the cost of having this formant in any track is (80/400) · 1.0 = 0.200. So we see that the procedure locally favours the inclusion of candidates with low relative bandwidths.

transitionCost

Described by the Praat manual as the cost of having two different consecutive formant values in a track. For instance, if a proposed track through the candidates has two consecutive formant values of 300 Hz and 424 Hz, and Transition cost is 1.0/octave, the cost of having this large frequency jump is (0.5 octave) · (1.0/octave) = 0.500.

windowShape

the analysis window function used when extracting part of a sound file for analysis. De faults to "Hanning".

relativeWidth

the relative width of the windowing function used.

spectWindowShape

The shape of the windowing function used for constructing the spectrogram.

spectResolution

The frequency resolution of the spectrogram from which formant intensities will be collected.

toFile

write the output to a file? The file will be written in outputDirectory, if defined, or in the same directory as the soundfile.

explicitExt

the file extension that should be used.

outputDirectory

set an explicit directory for where the signal file will be written. If not defined, the file will be written to the same directory as the sound file.

verbose

Not implemented. Only included here for compatibility.

praat_path

give an explicit path for Praat.

maxhzformant

praat will try to find formants only up to this frequency in the spectrum.

Value

Ar an SSFF track data object (if toFile=FALSE) containing three fields ("F", "B" and "L") containing formant frequencies, bandwidths and intensities.

Details

If the user only want to estimate formant frequencies, computing them using the function wrassp::forest is much quicker, and the user should therefore mainly consider using this function praat_formant_burg only if the use case specifically demands the use of the burg algorithm for computing formants, or if the user wants to also study the formant intensity levels (L_n) which wrassp::forest does not do.

have_praat functions.

See also

wrassp::forest

praat_formantpath_burg