soundgen (version 2.4.0)

modulationSpectrumFragment: Modulation spectrum per fragment

Description

Internal soundgen function.

Usage

modulationSpectrumFragment(
  sound,
  samplingRate,
  windowLength,
  windowLength_points,
  step,
  step_points,
  wn = "hanning",
  zp = 0,
  logSpec = FALSE,
  power = 1
)

Arguments

sound

numeric vector

samplingRate

sampling rate of x (only needed if x is a numeric vector)

windowLength

length of FFT window, ms

step

you can override overlap by specifying FFT step, ms (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)

wn

window type accepted by ftwindow, currently gaussian, hanning, hamming, bartlett, rectangular, blackman, flattop

zp

window length after zero padding, points

logSpec

if TRUE, the spectrogram is log-transformed prior to taking 2D FFT

power

raise modulation spectrum to this power (eg power = 2 for ^2, or "power spectrum")

Examples

# NOT RUN {
s = soundgen(amFreq = 25, amDep = 100)
ms = soundgen:::modulationSpectrumFragment(s, 16000,
  windowLength = 50, windowLength_points = .05 * 16000,
  step = 5, step_points = .005 * 16000)
image(as.numeric(colnames(ms$ms_half)), as.numeric(rownames(ms$ms_half)),
      t(log(ms$ms_half)))
# }