Extract formants from a sound object (DEPRECATED)

**DEPRECATED:** This function is deprecated in favor of the R6 interface. Use `sound$to_formant_burg()` instead.

Usage

extract_formants(
  sound,
  time_step = 0,
  max_formant = 5500,
  n_formants = 5,
  window_length = 0.025,
  pre_emphasis_from = 50
)

Arguments

sound

A praat_sound object created by read_sound or create_sound

time_step

Time step in seconds for formant analysis (0 = auto: 4x Nyquist)

max_formant

Maximum formant frequency in Hz (default: 5500 for adult female, use 5000 for adult male, 8000 for child)

n_formants

Number of formants to track (default: 5)

window_length

Analysis window length in seconds (default: 0.025)

pre_emphasis_from

Pre-emphasis frequency in Hz (default: 50)

Value

Depends on the class of sound:

• If sound is an R6 Sound object (the normal case — Sound()/Sound$create_tone() always create one), this function delegates entirely to sound$to_formant_burg() and returns an R6 Formant object. This is what get_formant_at_time/get_mean_formant do NOT accept — those two expect the legacy list below.

• If sound is a legacy (pre-R6) praat_sound list, returns a plain, unclassed list with elements values (a data.frame with columns time, formant_number, frequency, bandwidth), n_frames, time_step, max_formant, and n_formants. This list is no longer given a "praat_formant" class (removed when the package's S3 object system was fully migrated to R6), so it will not satisfy is_praat_formant() / get_formant_at_time / get_mean_formant without manually adding class(x) <- "praat_formant" first.

Details

Analyzes formant frequencies (vocal tract resonances) from a sound object using Praat's Burg algorithm.

Examples

# sound is an R6 Sound object here, so this delegates to to_formant_burg()
# and returns an R6 Formant object (see the second value's \value above).
sound <- Sound$create_tone(frequency = 220, duration = 0.5, sampling_rate =
 16000)
formants <- extract_formants(sound, max_formant = 5500)
#> Warning: extract_formants() is deprecated and will be removed in v6.0.0. Use the R6 interface: sound$to_formant_burg()
f1_mean <- formants$get_mean(formant_number = 1)

# Equivalent, and the recommended way to spell it directly:
formants2 <- sound$to_formant_burg(max_frequency = 5500)
f1_mean2 <- formants2$get_mean(formant_number = 1)