# pwelch: Welch's Power Spectral Density Estimate In phonTools: Tools for Phonetic and Acoustic Analyses

## Description

Calculates a power spectral density estimate using Welch's method.

## Usage

 ```1 2 3``` ```pwelch (sound, points = 0, overlap = 0, padding = 0, window = 'hamming', show = TRUE, fs = 1, preemphasisf = 0, zeromax = TRUE, type,...) ```

## Arguments

 `sound` A vector representing a sound wave, or a 'sound' object. `points` The number of points to be included in each window. If not specified, the sound is divided into 10 equally-sized windows. `overlap` The amount of overlap between adjacent segments, in points. `padding` The amount of zero padding to be applied to each window. `window` The window to be applied to each segment of the signal. See windowfunc() for available options. `show` If FALSE, no plot is created. `fs` The sampling frequency of the sound. If a 'sound' object is passed this does not need to be specified. `preemphasisf` Preemphasis of 3 dB per octave is added to frequencies above the specified frequency. `zeromax` If TRUE, the maximum dB is set to 0. `type` The line type to be used for plotting, passes its value to the 'lty' parameter. `...` any additional arguments will be passed to the internal calls of 'plot'.

## Details

This function divides the signal into a number of equally-sized windows, finds the power spectrum of each one, and then finds the average across all windowed sections.

## Value

The following columns:

 `hz` The center frequency of the analysis bins. `dB` The dB magnitude/power for the analysis bin.

## Author(s)

Santiago Barreda <sbarreda@ucdavis.edu>

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10``` ```## make a sine wave sinewave = sinusoid (f = 300, fs = 1000, dur = 2000, sum = FALSE) ## add noise sinewave = sinewave[,2] + rnorm (length (sinewave[,2]), 0, 3) ## compare the results of pwelch() and spectralslice() par (mfrow = c(2,1), mar = c(4,4,1,1)) spectralslice (sinewave, fs = 1000) pwelch (sinewave, points = 400, fs = 1000) ```

phonTools documentation built on May 1, 2019, 6:26 p.m.