Praat for Beginners
The Objects window: the control centre of Praat
1. The Objects window
2. The objects list
- The Objects list contains all the data (sound recordings, analyses, syntheses etc), that you have loaded for your work. You may typically start with a sound signal (open a sound file or record a new signal), and continue by doing analyses that are added to the list as they are done. Each of these data items is referred to in Praat as an object.
- This example lists two items: Sound Pgev01a and Spectrogram Pgev01a
- The first word indicates the data type, set by Praat:
- Sound: a Sound object containing a sound recording
- Spectrogram: a Spectrogram object containing a completed spectral analysis for a spectrogram
- Examples of other data objects not see here:
- Formant objects (formant tracks)
- LPC objects (the result of linear predictive analysis on a sound signal)
- Spectrum objects (amplitude/frequency spectra by FFT or LPC)
- The terms formant, LPC, linear prediction, spectrum, FFT will be
explained elsewhere as they arise
- The second word is the name of this data, provided by you. It is practical to choose names systematically according to some principle depending on the nature of your work, e.g in this example:
- Pgev: is a particular informant
- 01: is the first set of utterances for that informant
- a: is the first utterance in that set
- A data item is selected by marking it with a mouse click. Sound signal Pgev01a is selected in this example.
- Note that loaded data objects in Praat are not the same thing as open files in other programs (like word processors). Praat objects are held in working memory and disappear when the Praat session is ended, unless you decide yourself to save them as files.
- The amount of working memory fitted to your computer limits how much data can be loaded at any one time.
- Using working memory also means that your work is volatile and can be lost through misadventure such as a power failure. Your only protection is to continually save what you have done, especially sound data, pictures, and perhaps analyses involving much work.
- Keep full notes of your progress, dates and times, file names and what is in files, analyses you have performed along with analysis parameter settings, and so on. You might think you have it all in your head today, but next week …
- Data objects can be saved as files, but this is something you decide yourself. Note that there is nothing in the Objects list to indicate whether you have saved your data
- If you save a data object as a file on the hard disk, and then modify the data object as you work on it, that modification is not saved to the file unless you do it yourself.
- If you remove a data object from the list, there is no warning about first saving it to a file; you have to keep track of that yourself.
- However, when you exit Praat, you will be reminded if you still have data objects in memory and you will have an opportunity to cancel the exit and go back to save them if you wish.
3. The Actions menu
4. Editing buttons
- These buttons have useful housekeeping functions
- Three of these buttons (Rename, Copy, Remove) allow you to do just that: rename a selected data object, duplicate it or delete it. Note, these operations are only performed on the data objects listed in the Objectswindow. Corresponding data files are not affected by these buttons, whether or not any changes to the data object have been saved.
- Rename: Select the data object you wish to rename, click the Rename button, and alter the object’s name in the editing box that pops up; if you make a mistake you can cancel the operation before completing it. There is no Undo function, but you can repeat the procedure and put things right manually if you make a mistake
- Copy: Select the data object you wish to duplicate, click the Copy button, and write a name for the duplicate in the editing box that pops up; this box offers you the original name to start with, and Praat will allow you to keep this same name for the duplicate (you will then have two distinct but visually indistinguishable objects with the same name that you can subsequently manipulate independently); you can always rename the duplicate later if necessary
- Remove: Select the data object or objects you wish to delete, then click the Remove button. Watch out, this action is terminal and cannot be undone; there is no warning, the data is destroyed. If you need to have the data saved to a file on the hard disk, do that before clicking the Remove button
- There are two other buttons here:
- Info provides statistics on a selected data object
- Inspect displays the values of the individual data points of the selected data, and allows them to be edited. Do not edit this data unless you know what you are doing and why you are doing it.