generateHarmonics: Generate harmonics
In tatters/soundgen_beta: Parametric Voice Synthesis

Description Usage Arguments Details Examples

Internal soundgen function.

generateHarmonics(pitch, attackLen = 50, nonlinBalance = 0, nonlinDep = 0,
  jitterDep = 0, jitterLen = 1, vibratoFreq = 100, vibratoDep = 0,
  shimmerDep = 0, creakyBreathy = 0, rolloff = -18, rolloffOct = -2,
  rolloffKHz = -6, rolloffParab = 0, rolloffParabHarm = 3,
  rolloffLip = 6, rolloff_perAmpl = 12, temperature = 0,
  pitchDriftDep = 0.5, pitchDriftFreq = 0.125,
  randomWalk_trendStrength = 0.5, shortestEpoch = 300, subFreq = 100,
  subDep = 0, amDep = 0, amFreq = 30, amplAnchors = NA, overlap = 75,
  samplingRate = 16000, pitchFloor = 75, pitchCeiling = 3500,
  pitchSamplingRate = 3500, throwaway = -120)

`pitch`	a contour of fundamental frequency (numeric vector). NB: for computational efficiency, provide the pitch contour at a reduced sampling rate pitchSamplingRate, eg 3500 points/s. The pitch contour will be upsampled before synthesis.
`attackLen`	duration of fade-in / fade-out at each end of syllables and noise (ms)
`nonlinBalance`	hyperparameter for regulating the (approximate) proportion of sound with different regimes of pitch effects (none / subharmonics only / subharmonics and jitter). 0% = no noise; 100% = the entire sound has jitter + subharmonics. Ignored if temperature = 0
`nonlinDep`	hyperparameter for regulating the intensity of subharmonics and jitter, 0 to 100% (50% = jitter and subharmonics are as specified, <50% weaker, >50% stronger). Ignored if temperature = 0
`jitterDep`	cycle-to-cycle random pitch variation, semitones
`jitterLen`	duration of stable periods between pitch jumps, ms. Use a low value for harsh noise, a high value for irregular vibrato or shaky voice
`vibratoFreq`	the rate of regular pitch modulation, or vibrato, Hz
`vibratoDep`	the depth of vibrato, semitones
`shimmerDep`	random variation in amplitude between individual glottal cycles (0 to 100% of original amplitude of each cycle)
`creakyBreathy`	hyperparameter for a rough adjustment of voice quality from creaky (-1) to breathy (+1)
`rolloff`	basic rolloff at a constant rate of `rolloff` db/octave (exponential decay). See `getRolloff` for more details
`rolloffOct`	basic rolloff changes from lower to upper harmonics (regardless of f0) by `rolloffOct` dB/oct. For example, we can get steeper rolloff in the upper part of the spectrum
`rolloffKHz`	rolloff changes linearly with f0 by `rolloffKHz` dB/kHz. For ex., -6 dB/kHz gives a 6 dB steeper basic rolloff as f0 goes up by 1000 Hz
`rolloffParab`	an optional quadratic term affecting only the first `rolloffParabHarm` harmonics. The middle harmonic of the first `rolloffParabHarm` harmonics is amplified or dampened by `rolloffParab` dB relative to the basic exponential decay.
`rolloffParabHarm`	the number of harmonics affected by `rolloffParab`
`rolloffLip`	the effect of lip radiation on source spectrum, dB/oct (the default of +6 dB/oct produces a high-frequency boost when the mouth is open)
`rolloff_perAmpl`	as amplitude goes down from max to `throwaway`, `rolloff` increases by `rolloff_perAmpl` dB/octave. The effect is to make loud parts brighter by increasing energy in higher frequencies
`temperature`	hyperparameter for regulating the amount of stochasticity in sound generation
`pitchDriftDep`	scale factor regulating the effect of temperature on the amount of slow random drift of f0 (like jitter, but slower): the higher, the more f0 "wiggles" at a given temperature
`pitchDriftFreq`	scale factor regulating the effect of temperature on the frequency of random drift of f0 (like jitter, but slower): the higher, the faster f0 "wiggles" at a given temperature
`randomWalk_trendStrength`	try 0 to 1 - the higher, the more likely rw is to get high in the middle and low at the beginning and end (ie max effect amplitude in the middle of a sound)
`shortestEpoch`	minimum duration of each epoch with unchanging subharmonics regime, in ms
`subFreq`	target frequency of subharmonics, Hz (lower than f0, adjusted dynamically so f0 is always a multiple of subFreq)
`subDep`	the width of subharmonic band, Hz. Regulates how quickly the strength of subharmonics fades as they move away from harmonics in f0 stack. Low values produce narrow sidebands, high values produce uniformly strong subharmonics
`amDep`	amplitude modulation depth, modulation with amplitude range equal to the dynamic range of the sound
`amFreq`	amplitude modulation frequency, Hz
`amplAnchors`	a numeric vector of amplitude envelope (0 to 1) or a dataframe specifying the time (ms) and value of amplitude anchors
`overlap`	FFT window overlap, %
`samplingRate`	sampling frequency, Hz
`pitchFloor`	lower & upper bounds of f0
`pitchCeiling`	lower & upper bounds of f0
`pitchSamplingRate`	sampling frequency of the pitch contour only, Hz. Low values reduce processing time. A rule of thumb is to set this to the same value as `pitchCeiling`
`throwaway`	discard harmonics and noise that are quieter than this number (in dB, defaults to -120) to save computational resources

Returns one continuous, unfiltered, voiced syllable consisting of several sine waves.

pitch=soundgen:::getSmoothContour(len = 3500,
  anchors = data.frame('time' = c(0, 1), 'value' = c(200, 300)))
plot(pitch)
sound = soundgen:::generateHarmonics(pitch, samplingRate = 16000)
# playme(sound, samplingRate = 16000) # no formants yet