Track pitch using the Modified Harmonic Sieve algorithm

Estimates pitch in Hz using Michel Scheffers' Modified Harmonic Sieve (MHS) algorithm implemented in the libassp C library (Scheffers 2012) . MHS operates in the frequency domain and is robust to noise; it is a complementary alternative to the waveform-based trk_pitch_ksv.

Usage

trk_pitch_mhs(listOfFiles, beginTime = 0, centerTime = FALSE, endTime = 0, windowShift = 5, gender = "u", maxF = 600, minF = 50, minAmp = 50, minAC1 = 0.25, minRMS = 18, maxZCR = 3000, minProb = 0.52, plainSpectrum = FALSE, toFile = FALSE, explicitExt = "pit", outputDirectory = NULL, assertLossless = NULL, logToFile = FALSE, convertOverwrites = FALSE, keepConverted = FALSE, verbose = TRUE)

Arguments

listOfFiles: Character vector of audio file paths. Any format supported by av is accepted; non-native inputs are transcoded automatically.
beginTime: Numeric. Start of analysis window in seconds. Default 0 (file start).
centerTime: Numeric or logical. Single-frame analysis time point in seconds; overrides beginTime, endTime, and windowShift. Default FALSE.
endTime: Numeric. End of analysis window in seconds. Default 0 (file end).
windowShift: Numeric. Frame shift in milliseconds; sets output frame rate (1000 / windowShift Hz). Default 5 ms.
gender: Character. Gender-specific pitch search range: "f" (female), "m" (male), "u" (unknown, default).
maxF: Numeric. Maximum pitch in Hz. Default 600.0.
minF: Numeric. Minimum pitch in Hz. Default 50.0.
minAmp: Numeric. Minimum signal amplitude threshold. Default 50.0.
minAC1: Numeric. Minimum first autocorrelation coefficient. Default 0.25.
minRMS: Numeric. Minimum RMS amplitude in dB for voiced detection. Default 18.0.
maxZCR: Numeric. Maximum zero-crossing rate in Hz for voiced detection. Default 3000.0.
minProb: Numeric. Minimum harmonic sieve fit quality (0–1) for a frame to be considered voiced. Default 0.52.
plainSpectrum: Logical. Use plain (non-pre-emphasised) spectrum. Default FALSE.
toFile: Logical. If TRUE, write SSFF output files and return the count written (invisibly). If FALSE, return an AsspDataObj. Default FALSE.
explicitExt: Character. Output file extension. Default "pit".
outputDirectory: Character. Directory for output files. NULL (default) writes alongside the input file.
assertLossless: Character vector of additional file extensions to treat as losslessly encoded.
logToFile: Logical. Write processing log to a file in outputDirectory rather than the console. Default FALSE.
convertOverwrites: Logical. Allow transcoding to overwrite existing files. Default FALSE.
keepConverted: Logical. Retain intermediate transcoded files. Default FALSE.
verbose: Logical. Print per-file progress. Default FALSE.

Value

If toFile = FALSE: an AsspDataObj with track:

pitch[Hz]: REAL32, Hz, n_frames x 1 column. Estimated pitch frequency; 0 indicates unvoiced frames.

Frame rate: 1000 / windowShift Hz (default 200 Hz). If toFile = TRUE: integer count of files written, returned invisibly.

Details

Voicing is determined by joint thresholds on minAmp, minAC1, minRMS, maxZCR, and minProb. Increase minProb to reduce false voiced decisions in noisy conditions.

References

Scheffers M (2012). “Advanced Speech Signal Processor.” https://sourceforge.net/projects/libassp/files/libassp/.

Author

Raphael Winkelmann

Lasse Bombien

Fredrik Nylén

Examples

# get path to audio file
path2wav <- list.files(system.file("samples","sustained", package = "superassp"), pattern = glob2rx("a1.wav"), full.names = TRUE)

# calculate short-term autocorrelation
res <- trk_pitch_mhs(path2wav, toFile=FALSE)
#> Applying `method(trk_pitch_mhs, class_character)()` to 1 recording

# plot fundamental frequency contour
plot(seq(0, n_records(res) - 1) / sample_rate(res) +
       attr(res, 'startTime'),
     res[["pitch[Hz]"]],
     type='l',
     xlab='time (s)',
     ylab="Pitch (Hz)")