Sound objects

Praat for Beginners:
Tutorial: Sound objects and LongSound objects

1. Sound objects and LongSound objects
2. The difference between Sound objects and LongSound objects
3. What you can do with Sound objects and LongSound objects
4. Opening Sound objects and LongSound objects

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1. Sound objects and LongSound objects

• This is the sound data you work with in Praat – to listen to, to edit, or to analyse.
• This sound data – these sound objects – come from two sources:
  • From new recordings you’ve just made in the Sound recorders
  • From sound files you’ve just opened from storage (hard disks, memory sticks and cards, CDRoms etc)
• All digital sound data has its ultimate origin in recordings from a microphone, wherever it has been in the meantime. So you can just as well see these Praat sound data objects as sound recordings, just as you do for gramophone discs, cassette tapes, AudioCDs etc.

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2. The difference between Sound objects and LongSound objects

• A Sound object is loaded completely into computer memory
• A LongSound object is loaded a little at a time as needed

• There’s no fixed size difference between a Sound object and a LongSound object
• The absolute limit for a Sound object depends on your computer resources (working memory and virtual memory). The largest sound file that Praat can open as a Sound object on my computer is 200MB. But that limit falls rapidly as I load more and more Sound objects, until it’s down to 20MB or smaller.
• A sensible workflow will only need a few Sound objects loaded, to avoid taxing your computer’s resources.
• If you try to open a file that’s too large to be a Sound object, you get a warning:

• Click OK, then open the file as a LongSound object instead.
• A new recording in a Sound recorder is sometimes too large to be a Sound object:
  • Maybe you reset the recorder buffer to more than the default 20MB.
  • Maybe you have too many large Sound objects already loaded.
• When you transfer the new recording to the Objects list you get the same warning.
• Your recording is still safe in the recording buffer, so long as you don’t make a new recording or close the Sound recorder.
• Instead, save the recording as a sound file from the File menu in the Sound recorder.

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3. What you can do with Sound objects and LongSound objects

• You can do more with a Sound object than with a LongSound object
• For example, in the Sound editor, you can’t do the following with a LongSound object:
  • Cut and paste
  • Silence or reverse selections
  • Start and end selections at the nearest zero crossings
• These two pictures show you what you can do with a Sound object (left) and a LongSound object (right) in the Objects window:

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4. Opening Sound objects and LongSound objects

• Sound objects and LongSound objects are opened from the Open menu
  in the Objects window:
• Praat opens Sound objects and LongSound objects differently:

• Read from file opens a Sound object
• Open long sound file opens a LongSound object

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©Sidney Wood and SWPhonetics, 1994-2012