Praat Demonstration

Script snippets to demonstrate phonetics research and signal processing.

All the scripts below can be downloaded via GitHub.

Check out Praat script guide for the tips of using Praat scripts.

demo_amplitudeModulation

This script applies amplitude modulation, using a carrier signal (typically a high-frequency signal) to modulate the message signal (e.g. a speech utterance).

Select a Sound object as the message signal, run the script. The output will be a Sound object that's the modulated sound. If the Delete carrier option it not ticked, the carrier Sound object will also be added to the list.

demo_convolution

This script creates few basic waveforms (rectangular, sine, and two triangular shapes), which can be useful to demonstrate convolution (by "select two objects -> Combine -> Convolve").

It also provides few examples of convolution, cross-correlation and autocorrelation with these waveforms.

demo_damping

A Praat graphical demonstration script showing the effects of filter bandwidth on a wave harmonic component.

Run the script to open up the individual window, then change the settings based on the buttons and instructions on the screen.

demo_HappyPhonetician

Let's admit it: as Phoneticians we are typically very proud about the fancy looking analysis graphs we are producing in our daily work. With this script you can get a nice selection of typical speech analysis graphs (spectrogram, pitch curve, formant tracks, etc.) of a short section of speech, e.g. your name. Printed on a t-shirt this can be the ideal birthday or Xmas gift which, as experience shows, makes everybody freeze in awe in front of the amazingly complicated analysis we are able to perform.

This script prints waveform, spectrogram, formants, pitch, and intensity of a sound file into the 'Praat picture' window. It will print the name of the file as a headline. I use it with students at christmas so they can get an acoustic analysis of their names on one printout which is usually something that phoneticians like to hang up at home or print on their t-shirts - the more complicated the graphs look the better 😉.

demo_harmonicDistortion

This script demonstrates the effects of harmonic distortion on a sinusoid of 100 Hz and a vowel /a/ with 100 Hz fundamental frequency.

Run the script to open up the individual window, then change the settings based on the buttons and instructions on the screen.

demo_HNRinBeatingSuonds

This script repeatedly generates pairs of pure tones—one fixed at 200 Hz and the other varying from 200 Hz up to 300 Hz. For each pair, it measures the harmonic-to-noise ratio (HNR) of the resulting combined signal and prints the HNR value, exploring how changing the second tone’s frequency relative to a fixed 200 Hz tone affects the harmonic quality of the combined sound.

Run the script to generate Sound objects that're different combinations of frequencies. Inspect (view) these sound for more information.

demo_pulseTrain

This script demonstrates the effects of increasing and decreasing fundamental frequency in a pulse train on its spectrum. You should learn that the frequency spectrum gets denser as the frequency of the pulse train increases until there is only one pulse left and maximum density is reached (all frequencies are present at the same amplitude.

Run the script to open up the individual window, then change the settings based on the buttons and instructions on the screen.

demo_quantisation

This script demonstrates the effects of quantisation at different numbers of quantisation levels on a variety of waveforms (sinusoid, noise, vowel, synthesised speech).

Run the script to open up the individual window, then change the settings based on the buttons and instructions on the screen.

demo_requantiseSpeech

This program simulates a change of the number of quantisation levels. It changes a sound waveform to what it would look like if it was quantised with varying numbers of bit levels. The actual number of quantisation levels of the sound, however, is not affected (this is necessary because Praat (version 5.2.11) cannot process files lower than 8 bit).

Select a Sound object containing a speech and run the script. A re-quantised Sound object will be generated and added to the list.

demo_sourceFilterSynthesier

This script visualises a Klatt formant synthesis and lets the user change pitch and formant frequencies.

Run the script to open up the individual window, then change the settings based on the buttons and instructions on the screen.

👏 Another recommendation that're also fun and intuitive to play around: Pink Trombone.

demo_uncertaintyPrinciple

A Praat demonstration allowing users to interactively explore how altering a sound’s amplitude, type (sine, vowel, noise), and viewing ranges affects its time-domain waveform and frequency-domain spectrum, illustrating the uncertainty principle in signal analysis.

Run the script to open up the individual window, then change the settings based on the buttons and instructions on the screen.

rhythmCreator

This script creates series of rhythmic clicks that vary in rhythm and rate.

Run this script, the created rhythm Sound object will be added to the Praat object list.