extract_mfcc: Extract MFCCs for vowel segments

In phontrast: Contrast and Separation Metrics for Phonological Categories

Extract MFCCs for vowel segments

Description

Adds MFCC feature columns (e.g., mfcc1..mfcc13) to a data frame that contains audio file paths and (optionally) segment boundaries.

Usage

extract_mfcc(
  data,
  file_col,
  start_col = NULL,
  end_col = NULL,
  fs = NULL,
  numcep = 13,
  prefix = "mfcc",
  strict = FALSE,
  warn = TRUE,
  ...
)

Arguments

data	Data frame containing audio paths and segment boundaries.
file_col	String; column name containing WAV file paths.
start_col	Optional string; column name containing segment start time (in seconds). If NULL, the full file is used.
end_col	Optional string; column name containing segment end time (in seconds). If NULL, the full file is used.
fs	Optional numeric; override sampling rate (Hz). If NULL, uses the file's sampling rate.
numcep	Integer; number of MFCC coefficients to return.
prefix	String; prefix for output columns (default "mfcc").
strict	Logical; if TRUE, stop on the first row that cannot be processed. If FALSE (default), leave that row's MFCC values as NA.
warn	Logical; if TRUE (default), warn when one or more rows cannot be processed and strict = FALSE.
...	Additional arguments passed to tuneR::melfcc().

Details

This function uses tuneR to read WAV files and compute MFCCs. The package is optional; if it is not installed, an informative error is raised.

Value

The input data frame with added MFCC columns.

Examples

if (requireNamespace("tuneR", quietly = TRUE)) {
  wav_path <- tempfile(fileext = ".wav")
  wave <- tuneR::sine(
    freq = 440, duration = 0.25, samp.rate = 16000, xunit = "time"
  )
  tuneR::writeWave(wave, wav_path)

  segments <- data.frame(wav_path = wav_path)
  mfcc <- extract_mfcc(segments, file_col = "wav_path", numcep = 3)
  unlink(wav_path)
  mfcc[, c("mfcc1", "mfcc2", "mfcc3")]
}

phontrast documentation built on Oct. 7, 2026, 5:06 p.m.