What a Sound Looks Like

This section helps you to understand what a temporal signal is, the spectrum and the time-frequency representation of a sound (or audio file).

The temporal, spectral and time-frequency representations of the audio file, Speech-LeMasquage.wav, are presented below:

The sound Speech-LeMasquage.wav is located in the SoundSamples\TestSounds.

• Temporal representation, also called waveform

  The following signal waveform is typical of human voices.

  Figure 1. On the left is the overview of the signal waveform. On the right is the zoom in the signal waveform showing a peak in a period.
  

• Spectral representation or spectrum

  Figure 2. On the left is the overview of the signal spectrum, computed on the whole signal. On the right is the zoom in the signal spectrum, computed on a stationary signal.
  

• Time-frequency representation

  Figure 3. The overview of the signal time-frequency representation.