Praat Scripting for fun and (minimal) profit

Will Styler - Fall 2016

### What you cannot do with Praat scripting

* Label your data/speech recognition * You can label known data with “Forced Alignment”

* Work with programs that aren’t Praat (*)

* Run statistics on your data

* … but you can dump your data into R!

* Anything that you can’t, eventually, do through the Praat UI

* Generate measurements as consistent as hand measurements

* … but you can definitely do some things more easily!

What is a Praat script?

A file with a series of commands for Praat and comments for humans

When scripting, you will need to be a bit more specific than you would with a human…

Computers are stupid: They do exactly what you tell them to.

# This is a comment, Praat ignores lines that start with #
# Get the selected sound
soundname$ = selected$ ("Sound")
select Sound 'soundname$'
# Rename it!
Rename... 'soundname$'_resampled
# Resample it, then write to file!
Resample... 10000 50
Write to WAV file... ‘soundname$‘_10000.wav

Praat has changed some of the scripting commands to become “more modern”

The ones in this slideshow still work, though!

Your very first Praat script

Let’s automate something you do all the time, in the same way each time
Like making a broadband vs. narrowband spectrogram

Open Praat, then go to “New Praat Script”

Capturing the commands using “History”

Now, open a sound, and narrow the spectrogram

Then, go to the script window and “Paste History”

History saves everything you do in Praat

This is the best (and sometimes only) way to find different Praat commands.

Almost done!

You now have a few lines, one of which looks like …

Spectrogram settings… 0 5000 0.05 50
That’s your first script. Make that line the only thing in the script window
Now save the script someplace handy, narrowband.praat
Now, you can add it to any menu as described in Section 11.2.2 of Using Praat for Linguistic Research
You just wrote your first Praat script!

Praat scripting commands resemble the commands in the GUI

Spectrogram settings… 0 5000 0.005 50

You can make the spectrogram broad-band again!

Spectrogram settings… 0 5000 0.025 50

To go fancier, we need more scripting knowledge!

(Some of this will be review for many of you, sorry!)

Variables are like pronouns for data.

“Remember whats-his-name, that guy who brought the great pecan pie last year?”

“Yeah…?”

“Invite whats-his-name to Thanksgiving this year!”

whatshisname$ = Find guy who brought pecan pie

party-invite whatshisname$

Assigning Variables

variable = 1000

variable = Get number of intervals... '1'

start = Get starting point... 1 2

end = Get end point... 1 2

midpoint = start + ((end - start) / 2)

Get vocal tract length from F3 at cursor

f3h = Get third formant
length = (1715/(4 * f3h))
lcm = length * 100
print Your vocal tract length is 'lcm:1' cm

Getting a bit fancier

Sometimes, you want to automate more than one command

You can put multiple lines into a file, and Praat runs through them at a single command!

# Get the selected sound
soundname$ = selected$ ("Sound")
select Sound 'soundname$'
# Rename it!
Rename... 'soundname$'_resampled
# Resample it, then write to file!
Resample... 10000 50
Write to WAV file... ‘soundname$‘_10000.wav

The Button/Skynet continuum

You can write scripts of various degrees of complexity
Some scripts run a single command quickly, and act as a new button
- The user is completely in control, but it’s relatively slow
Some scripts run a large process, but keep the user involved
- The user yields some control to gain speed
Some scripts go through a large process on their own, without your help
- Fastest, but you don’t control any of the process while it’s running

You’ll always trade control for speed of measurement

Be realistic about your needs, both in time and precision

Working across files

To work on many files, you need more than just the file(s) you have open

Giving Praat files and information

Praat doesn’t know what a vowel is, and can’t find them natively
Sound files are annotated for Praat by making “TextGrids”.

Textgrids are your way of giving Praat the information it can’t figure out on its own

Once you’ve got files and textgrids, you can then pull in a whole batch of files
Praat can do something to every one of those files.
This happens through the magic of…

‘for loops’

Let’s say you’re building a lot of toy cars…

‘for’ loops

For loops iterate through large amounts of data, doing the same thing each time.

They always have the format for [var] from 1 to [other var], followed by an indented block, ended with an endfor

select TextGrid Sound1
number_intervals = Get number of intervals... 2
for k from 1 to number_intervals
    int_start = Get starting point... 1 'k'
    int_end = Get end point... 1 'k'
    int_duration = (int_end - int_start)
    print int_duration
endfor
# This code gets the duration of every interval and prints it

Taking control with ‘if’ statements

‘if’ statements

Used when a given action happens only if another condition is met

Usually take the form if [var] = [value], indented block, endif

### If you want an example…

select TextGrid Sound1 number_intervals = Get number of intervals… 2 for k from 1 to number_intervals int_label$ = Get label of interval… 1 ‘k’ if int_label$ = “v” int_start = Get starting point… 1 ‘k’ int_end = Get end point… 1 ‘k’ int_duration = (int_end - int_start) print int_duration endif endfor

Other Residents of Script-land

# at the start of the line means ‘comment’, Praat will ignore the line
Adding a :number to a variable name ( variable:2 ) will round to that number of decimal places
The print command will print whatever follows it into the info window
- print duration will print the contents of the variable duration
- print “duration” will print the word “duration”
- This is useful for debugging (print variables which might be bad!)

Praat is weird

Don’t put decimals or unicode in Filenames
The symbol for “not equal to” is <> in Praat, rather than != or something sane
You’ll have to describe folder/file locations differently on a Mac vs. Windows
- directory$ = “c:data" (Windows)
- directory$ = “/Users/will/Documents/test data/” (Mac)
Praat won’t always agree with itself from window to window
A single quotation mark can be your worst enemy

Sanity Checking

Humans only make sane measurements, computers don’t care
You know that his F0 is not 3000 Hz. Praat doesn’t.
You can figure out easily if the formant track is right. It definitely can’t.
Praat is a black box sometimes
You need to double-check everything, or your data could be subtly wrong

Debugging

Your script will crash more times than it runs
Look at the error message, look at the line number it mentions, start there
Sometimes, the error message will give you good information
print the contents of variables, to make sure it’s getting the right values
Use the “fail” command to crash the script at a given point (to make sure the script is getting there at all).
- Just keep moving the command until you know just where the error occurs.

Think before you automate

Automating a task will cost you time. Will you gain enough back?
Automating a task will add noise. Can you handle that?
Automating a task will remove control. Do you need to have control?

… but don’t be too reluctant

Time spent coding something is regained when you reuse it
You can build on your past approaches
Re-running the data basically comes free.
Most importantly, though…
You feel like a wizard.

Praat’s Scripting Help

It’s actually really good

In Defense of Cannibalism

Steal code.

If you find a script that does 90% of what you want, just add the 10% yourself
Give the author of the code credit with a comment
Don’t trust anybody else’s math
- Not even mine!
Some code is just bad

The majority of my scripts are open source

https://github.com/stylerw

Please steal them.

You will hate your life if you Praat script

Even after 10 years, I still have to debug everything I write, and regularly screw up.
You will get 50 crashes, caused by 50 little mistakes
You will question why you’re bothering with this, and where your life went wrong
You will feel like you are alone in your pain

… but suddenly, it will work

You’ll realize that your script hasn’t crashed
… and that data is pouring into the designated file
… and that the data looks OK
… and then, eventually, you have the greatest realization ever

And you will realize that the world is a wonderful place

… and you owe it all to Praat scripting

Get more scripting information

Download useful examples (as well as a fun guide on using Praat) from:

http://savethevowels.org/praat/

You can also see a more fleshed out version of this slide show here

… and please feel free to email me when you’re having trouble!

Let’s look at an example!

Example script is here

# This part presents a form to the user
form Measure Formants and Duration
    comment Sound file extension:
        optionmenu file_type: 2
        option .aiff
        option .wav
endform

directory$ = chooseDirectory$ ("Choose the directory containing sound files and textgrids")
# This will need to be changed to \ below for PC users
directory$ = "'directory$'" + "/" 
resultfile$ = "'directory$'"+"formantlog.txt"

header_row$ = "filename" + tab$ + "vowel" + tab$ + "Duration" + tab$ + "F1" +
tab$ + "F2" + tab$ + "F3" + newline$

fileappend "'resultfile$'" 'header_row$'

# List of all the sound files in the specified directory:
Create Strings as file list... list 'directory$'*'file_type$'
number_files = Get number of strings

# This opens all the files one by one
for j from 1 to number_files
    select Strings list
    filename$ = Get string... 'j'
    Read from file... 'directory$''filename$'
    soundname$ = selected$ ("Sound")
    filedur = Get total duration
    # identify associated TextGrid
    gridfile$ = "'directory$''soundname$'.TextGrid"
    if fileReadable (gridfile$)
        Read from file... 'gridfile$'
        select TextGrid 'soundname$'
        number_intervals = Get number of intervals... 1

# Go through each item
for k from 1 to number_intervals
    select TextGrid 'soundname$'
    int_label$ = Get label of interval... 1 'k'
    #checks if interval has a label
    if int_label$ <> ""
        # Calc start, end, and duration of interval
        intstart = Get starting point... 1 'k'
        intend = Get end point... 1 'k'
        intdur = intend - intstart
        intmid = intstart + (intdur / 2)

    # Get all the formants!
    select Sound 'soundname$'
    To Formant (burg)... 0 5 5500 0.025 50
    intf1 = Get value at time... 1 'intmid' Hertz Linear
    intf2 = Get value at time... 2 'intmid' Hertz Linear
    intf3 = Get value at time... 3 'intmid' Hertz Linear

    # Dump results into a file.
    result_row$ = "'filename$'" + tab$ + "'int_label$'" + tab$ + "'intdur'" + tab$ +
    "'intf1'" + tab$ + "'intf2'" + tab$ + "'intf3'" + newline$
    fileappend "'resultfile$'" 'result_row$'
endif
endfor
endif
endfor
# That's all!