phonTools (version 0.2-2.0)

powertrack: Power tracking

Description

Create a power track for a sound.

Usage

powertrack (sound, timestep = 5, windowlength = 30, 
            fs = 22050, show = TRUE, zeromax = TRUE, ...)

Arguments

sound

A numeric vector representing a waveform, or a 'sound' object created with the loadsound() or makesound() functions.

timestep

Determines how far the window will be moved for each adjacent analysis, in milliseconds.

windowlength

Determines how much of the signal is included for each analysis step, in milliseconds. If this is too small, pitch-synchronous ripples will be seen in the track.

fs

The sampling frequency of the sound. If a 'sound' or 'ts' object is passed, this does not need to be specified.

show

If TRUE, the track is plotted.

zeromax

If TRUE, the maximum dB value is set to zero.

...

Additional parameters are passed to the internal call of plot(), and used to create the figure.

Value

• A dataframe with the following columns:
• time
  The time, in milliseconds, of each point of analysis.
• power
  The power, in decibels, at each analysis point.

Details

Returns the average power in the signal in a section as determined by the parameters of the function. A Hann window is applied to each section prior to analysis. Sections with zero power are ignored and not returned.

Examples

## plot the waveform and power of a given sound.
data (sound)
# sound = loadsound()        ## run this line to use you own sound

## compare waveform and power
par (mfrow = c(2,1), mar = c(4,4,1,1));
plot (sound)
powertrack (sound)