Spectrogram

One of the types of objects in Praat. For tutorial information, see Intro 3. Spectral analysis.

A Spectrogram object represents an acoustic time-frequency representation of a sound: the power spectral density PSD (f, t), expressed in Pa2/Hz. It is sampled into a number of points centred around equally spaced times ti and frequencies fj.

## Inside a Spectrogram

With Inspect, you will see the following attributes:

xmin
  start time, in seconds.
xmax
  end time, in seconds.
nx
  the number of times (≥ 1).
dx
  time step, in seconds.
x1
  the time associated with the first column, in seconds. This will usually be in the range [xmin, xmax]. The time associated with the last column (i.e., x1 + (nx – 1) dx)) will also usually be in that range.
ymin
  lowest frequency, in Hertz. Normally 0.
ymax
  highest frequency, in Hertz.
ny
  the number of frequencies (≥ 1).
dy
  frequency step, in Hertz.
y1
  the frequency associated with the first row, in Hertz. Usually dy / 2. The frequency associated with the last row (i.e., y1 + (ny – 1) dy)) will often be ymax - dy / 2.
zij, i = 1 ... ny, j = 1 ... nx
  the power spectral density, in Pa2/Hz.

### Links to this page

- ConstantQLogFSpectrogram
- FormantFilter
- Formulas 1.7. Formulas for modification
- Formulas 8. Attributes of objects
- Intro 3.5. The Spectrogram object
- Sound & Pitch: To Spectrogram...
- Sound: To Spectrogram (pitch-dependent)...
- Sound: To Spectrogram...
- Source-filter synthesis 4. Using existing sounds
- spectro-temporal representation
- Spectrogram: Formula...
- Spectrogram: Paint...
- Spectrogram: To Spectrum (slice)...
- Spectrum: To Spectrogram
- time domain