Sound

One of the types of objects in Praat. For tutorial information, see all of the Intro.

### Commands

Creation:

Opening and saving:

You can also use the text and binary (real-valued) formats for Sounds, like for any other class:

Playing:

Viewing and editing:

Queries:

structure:
• time domain
• Get number of samples
• Get sampling period
• Get sampling frequency
• Get time from sample number...
• Get sample number from time...
content:
• Sound: Get value at time...
• Sound: Get value at sample number...
shape:
• Sound: Get minimum...
• Sound: Get time of minimum...
• Sound: Get maximum...
• Sound: Get time of maximum...
• Sound: Get absolute extremum...
• Sound: Get nearest zero crossing...
statistics:
• Sound: Get mean...
• Sound: Get root-mean-square...
• Sound: Get standard deviation...
energy:
• Sound: Get energy...
• Sound: Get power...
in air:
• Sound: Get energy in air
• Sound: Get power in air
• Sound: Get intensity (dB)

Modification:

Annotation (see Intro 7. Annotation):

Periodicity analysis:

Spectral analysis:

Filtering (see Filtering tutorial):

Conversion:

Enhancement:

Combination:

Synthesis

### Inside a Sound

With Inspect, you will see that a Sound contains the following data:

xmin
start time, in seconds.
xmax > xmin
end time, in seconds.
nx
the number of samples (≥ 1).
dx
sample period, in seconds. The inverse of the sampling frequency (in Hz).
x1
the time associated with the first sample (in seconds). This will normally be in the range [xmin, xmax]. The time associated with the last sample (i.e., x1 + (nx – 1) dx)) will also normally be in that range. Mostly, the sound starts at t = 0 seconds and x1 = dx / 2. Also, usually, xmax = nx dx.
z  [1..nx]
the amplitude of the sound (stored as single-precision floating-point numbers). For the most common applications (playing and file I-O), Praat assumes that the amplitude is greater than -1 and less than +1. For some applications (modelling of the inner ear; articulatory synthesis), Praat assumes that the amplitude is expressed in Pascal units. If these interpretations are combined, we see that the maximum peak amplitude of a calibrated sound is 1 Pascal; for a sine wave, this means 91 dB SPL.

### Limitations

Since the Sound object completely resides in memory, its size is limited to the amount of RAM in your computer. For sounds longer than a few minutes, you could use the LongSound object instead, which you can view in the LongSoundEditor.