23. Advanced speech analysis tools II: Praat and more

     Judging from mentions spotted on the Internet, Praat (Dutch for 'talk'), created by Paul Boersma and David Weenink of the Institute of Phonetic Sciences, University of Amsterdam, is currently among the most popular of free, downloadable speech analysis software packages. It is used in ESL courses for relatively basic functions, like making waveforms for students to compare their pronunciation against that of a native-speaker model. It is used in introductory phonetics classes for spectrogram making, pitch tracks, and other functions we have been using WASP for. And it is used for more complex kinds of analysis by those who are at an advanced level in their study of phonetics and know a bit about computer programming and 'script' writing. So Praat is highly flexible; you can use it to good advantage whatever your current level is.

     Praat can be downloaded from this page; click on 'Windows' (unless you use some other operating system; then click on the appropriate link):


     One big advantage of Praat is it includes a clear and very detailed user's manual to help you learn how to use Praat's many functions. After installing Praat, click on 'Help', and start going through the user's manual, page by page, to learn what you can do with Praat, and how to do it. In addition, Sidney Wood, formerly of Lund University, Sweden, has a helpful introductory tutorial on the use of Praat on his Website. The URL is:


     On the Praat homepage, you will also find a link to e-mail address of Prof. Pascal van Lieshout of the University of Toronto (or you can use this link), who has written a short tutorial for the Praat program. Just send him a note saying, 'Could you please send me a copy of your Praat tutorial?' and he will send you a pdf (Acrobat) file of this very clear and helpful tutorial. Although the tutorial was specifically written for clinicians in the field of communication disorders, it is a very accessible introduction for the general user as well.

     Here is a list of just a few of the things you can do with Praat, to get you started: you can generate waveforms, wide and narrow band spectrograms, and pitch tracks (as with WASP); you can play a recorded sound in reverse; you can further process a speech signal by filtering it (as with SFS: high-pass, low-pass, band-pass, band-stop); you can also enhance certain frequency regions; segment and label words, syllables, or individual phonemes; show an intensity contour; put your work in graphic form ('draw a plot') for printing; extract individual sounds for further analysis; and measure voice onset time (VOT). If you are interested in phonology, there are Optimality Theory tutorials and tools to make OT tableaux (look these terms up, if you are interested). You can even generate an animated outline model of a vocal tract making a particular sound! Praat's possibilities are seemingly endless.

     As with any new tool, it will take an investment of time and effort to learn how to make Praat do what you want it to do; but it is well worth it. Once you know how to use some of Praat's functions, you will have a very powerful set of learning and analysis tools at your disposal that can help bring you up to the next level in your study of phonetics. Don't rush! Learn a bit at a time, but keep at it every day for a while. You will feel a tremendous sense of accomplishment with each new skill you learn!

     In these two pages, we have introduced only two speech analysis software packages, SFS and Praat. There are many others available for you to try. Here is a partial list of these programs, with links to their introductory or download pages. Visit each site, try out the program offered if it appeals to you, and see what it can do. Decide for yourself which one or ones are best suited to your particular needs.

     WaveSurfer: An open source tool for sound visualization and manipulation; by Kåre Sjölander and Jonas Beskow of KTH (the Royal Institute of Technology) in Stockholm, Sweden

     SIL Speech Analysis software applications


    Mark Huckvale and UCL offer a number of interesting speech analysis programs besides WASP and SFS that you can explore:

     (1) SFS/Browse: Drag and drop audio files in a range of formats onto the display to see and hear their contents.

     (2) UCL Enhance: A program for the enhancement of the intelligibility of speech recordings. The program incorporates a number of standard techniques for manipulating the overall amplitude of the signal and for the removal of steady-state additive noise.

     (3) SFS/ESYNTH: A program designed to explain the harmonic analysis and synthesis of signals. With ESynth you can create signals by adding together individual sinusoidal waveforms (sinewaves) and study the resulting waveform and spectrum. You can also perform an analysis of an input waveform, to see how a given sound can be represented in terms of a sum of sinewaves.

     (4) SFS/ESYSTEM: See the effect of simple systems on a range of simple signals. You can generate simple signals such as sinewaves, pulses, pulse trains, sawtooth and noise; you can pass them though systems such as an amplifier, a resonator, a low-pass, high-pass or band-pass filter, or a vocal tract model.

     (5) SFS/RTSPECT Version 2.1: With this program you can monitor the waveform and spectral shape of sounds being played into the computer's microphone or line input ports.

     Here is a whole list of speech synthesis and analysis software, with links (some of which may be dead):

     My personal preferences: I use WASP for simple needs, like waveforms and spectrograms, because it is small, loads quickly, and is uncomplicated by lots of other features. I sometimes use SFS for features I have come to depend on it for, for some reason or other. But if I were to pick just one all-purpose program, it would definitely be Praat. It is not difficult to use, it has just about every conceivable function you will have occasion to use, and the help files are clear and truly helpful. The authors offer good support for their program. And it's free!

     We have learned about Daniel Jones's cardinal vowels in chapter 9 of Ladefoged's Course. From the next page, you will be able to link to recordings of the cardinal vowels made by Daniel Jones himself. The site that offers the recordings is based in the Netherlands, so don't panic when you discover that parts of the site are written in Dutch. You will be able to find your way around just fine!

Next: Daniel Jones's cardinal vowels (before this page is ready, you can link directly to the cardinal vowels page by clicking here; Peter Ladefoged has similar recordings on his site here)

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