lockToFormants: Lock to formants

In soundgen: Sound Synthesis and Acoustic Analysis

Lock to formants

Description

Internal soundgen function

Usage

lockToFormants(
  pitch,
  specEnv,
  formantSummary,
  rolloffMatrix = NULL,
  lockProb = 0.1,
  minLength = 3,
  plot = FALSE
)

Arguments

pitch	pitch contour, numeric vector (normally pitch_per_gc)
specEnv	spectral envelope as returned by getSpectralEnvelope
formantSummary	matrix of exact formant frequencies (formants in rows, time in columns)
rolloffMatrix	rolloff matrix as returned by getRolloff
lockProb	the (approximate) proportion of sound affected by formant locking
minLength	the minimum number of consecutive pitch values affected (shorter segments of formant locking are ignored)
plot	if TRUE, plots the original and modified pitch contour

Details

When f0 or another relatively strong harmonic is close to one of the formants, the pitch contour is modified so as to "lock" it to this formant. The relevant metric is energy gain (ratio of amplitudes before and after the adjustment) penalized by the magnitude of the necessary pitch jump (in semitones) and the amplitude of the locked harmonic relative to f0.

Examples

n = 50
pitch = getSmoothContour(len = n, anchors = c(600, 2000, 1900, 400),
  thisIsPitch = TRUE, plot = TRUE)
rolloffMatrix = getRolloff(pitch_per_gc = pitch)
specEnv = getSpectralEnvelope(nr = 512, nc = length(pitch),
  formants = list(f1 = c(800, 1200), f2 = 2000, f3 = c(3500, 3200)),
  lipRad = 0, temperature = .00001, plot = TRUE)
formantSummary = t(data.frame(f1 = c(800, 1200), f2 = c(2000, 2000), f3 = c(3500, 3200)))
pitch2 = soundgen:::lockToFormants(pitch = pitch, specEnv = specEnv,
  rolloffMatrix = rolloffMatrix,
  formantSummary = formantSummary,
  lockProb = .5, minLength = 5, plot = TRUE)
pitch3 = soundgen:::lockToFormants(pitch = pitch, specEnv = specEnv,
  rolloffMatrix = rolloffMatrix,
  formantSummary = formantSummary,
  lockProb = list(time = c(0, .7, 1), value = c(0, 1, 0)),
  minLength = 5, plot = TRUE)

soundgen documentation built on Sept. 29, 2023, 5:09 p.m.