msToSpec: Modulation spectrum to spectrogram

In soundgen: Sound Synthesis and Acoustic Analysis

Modulation spectrum to spectrogram

Description

Takes a complex MS and transforms it to a complex spectrogram with proper row (frequency) and column (time) labels.

Usage

msToSpec(ms, windowLength = NULL, step = NULL)

Arguments

ms	target modulation spectrum (matrix of complex numbers)
windowLength	length of FFT window, ms (multiple values in a vector produce a multi-resolution spectrogram)
step	you can override overlap by specifying FFT step, ms - a vector of the same length as windowLength (NB: because digital audio is sampled at discrete time intervals of 1/samplingRate, the actual step and thus the time stamps of STFT frames may be slightly different, eg 24.98866 instead of 25.0 ms)

Value

Returns a spectrogram - a numeric matrix of complex numbers of the same dimensions as ms.

Examples

s = soundgen(sylLen = 250, amFreq = 25, amDep = 50,
             pitch = 250, samplingRate = 16000)
spec = spectrogram(s, samplingRate = 16000, windowLength = 25, step = 5)
ms = specToMS(spec)
plotMS(log(Mod(ms)), quantiles = NULL, col = soundgen:::jet.col(100))
spec_new = msToSpec(ms)
spectrogram(s, specManual = Mod(spec_new))
## Not run: 
# or plot manually
image(x = as.numeric(colnames(spec_new)), y = as.numeric(rownames(spec_new)),
      z = t(log(abs(spec_new))), xlab = 'Time, ms',
      ylab = 'Frequency, kHz')

## End(Not run)

soundgen documentation built on Aug. 8, 2025, 7:47 p.m.