soundgen (version 2.7.2)

generateEpoch: Generate an epoch

Description

Internal soundgen function. Takes descriptives of a number of glottal cycles (f0, closed phase, rolloff) and creates a continuous waveform. The principle is to work with one epoch with stable regime of subharmonics at a time and create a sine wave for each harmonic, with amplitudes adjusted by rolloff.

Usage

generateEpoch(pitch_per_gc, epochs, rolloff_per_epoch, samplingRate)

Value

Returns a waveform as a non-normalized numeric vector centered at zero.

Arguments

pitch_per_gc

pitch per glottal cycle, Hz

epochs

a dataframe specifying the beginning and end of each epoch

rolloff_per_epoch

a list of matrices with one matrix for each epoch; each matrix should contain one column for each glottal cycle and one row for each harmonic (linear multiplier, ie NOT in dB). Rownames specify the ratio to F0 (eg 1.5 means it's a subharmonic added between f0 and its first harmonic)

samplingRate

the sampling rate of generated sound, Hz

Examples

pitch_per_gc = seq(100, 150, length.out = 90)
epochs = data.frame (start = c(1, 51),
                     end = c(50, 90))
m1 = matrix(rep(10 ^ (-6 * log2(1:200) / 20), 50), ncol = 50, byrow = FALSE)
m2 = matrix(rep(10 ^ (-12 * log2(1:200) / 20), 40), ncol = 40, byrow = FALSE)
rownames(m1) = 1:nrow(m1)
rownames(m2) = 1:nrow(m2)
rolloff_source = list(m1, m2)
s = soundgen:::generateEpoch(pitch_per_gc, epochs,
                             rolloff_source, samplingRate = 16000)
# plot(s, type = 'l')
# playme(s)