View audio waveforms and spectrums

In the Waveform Editor, the Editor panel provides a visual representation of sound waves. Below the panel’s default waveform display, which is ideal for evaluating audio amplitude, you can view audio in the spectral display, which reveals audio frequency (low bass to high treble).

  • To view the spectral display, do either of the following:.
    • In the toolbar, click the Spectral Display  button.
    • In the Editor panel, drag the divider between the waveform and spectral displays to change the proportion of each. To instantly show or hide the spectral display, double-click the handle or click the triangle to its right.
Viewing the waveform and spectral displays

A. Drag the divider to change the proportion of each. B. Click the triangle to show or hide the spectral display. 

Note:

To identify specific channels in stereo and 5.1 surround files, note the indicators in the vertical ruler.

About the waveform display

The waveform display shows a waveform as a series of positive and negative peaks. The x‑axis (horizontal ruler) measures time, and the y‑axis (vertical ruler) measures amplitude—the loudness of the audio signal. Quiet audio has both lower peaks and lower valleys (near the center line) than loud audio. You can customize the waveform display by changing the vertical scale and colors.

With its clear indication of amplitude changes, the waveform display is perfect for identifying percussive changes in vocals, drums, and more. To find a particular spoken word, for example, simply look for the peak at the first syllable and the valley after the last.

Stereo file in waveform display

About the spectral display

The spectral display shows a waveform by its frequency components, where the x‑axis (horizontal ruler) measures time and the y‑axis (vertical ruler) measures frequency. This view lets you analyze audio data to see which frequencies are most prevalent. Brighter colors represent greater amplitude components. Colors range from dark blue (low‑amplitude frequencies) to bright yellow (high‑amplitude frequencies).

The spectral display is perfect for removing unwanted sounds, such as coughs and other artifacts.

Spectral display, with high frequencies selected

View layered or uniquely colored waveform channels

For stereo and 5.1 surround files, you can view layered or uniquely colored channels. Layered channels better reveal overall volume changes. Uniquely colored channels help you visually distinguish them.

  • Choose View > Waveform Channels, and then select Layered or Uniquely Colored.

Channel View options

A. Uniquely Colored B. Layered (with Uniquely Colored still selected) 

Customize the spectral display

The Spectral Display preferences help you enhance different details and better isolate artifacts.

  1. Choose Edit > Preferences > Spectral Display (Windows) or Audition > Preferences > Spectral Display (Mac OS).

  2. Set the following options

    Windowing Function

    Determines the Fast Fourier transform shape. These functions are listed in order from narrowest to widest. Narrower functions include fewer surrounding frequencies but less precisely reflect center frequencies. Wider functions include more surrounding frequencies but more precisely reflect center frequencies. The Hamming and Blackman options provide excellent overall results.

    Spectral Resolution

    Specifies the number of vertical bands used to draw frequencies. As you increase resolution, frequency accuracy increases, but time accuracy decreases. Experiment to find the right balance for your audio content. Highly percussive audio, for example, may be better reflected by low resolution.

    Note:

    To adjust resolution directly in the Editor panel, right-click the vertical ruler next to the spectral display, and choose Increase or Decrease Spectral Resolution.

    Decibel Range

    Changes the amplitude range over which frequencies are displayed. Increasing the range intensifies colors, helping you see more detail in quieter audio. This value simply adjusts the spectral display; it does not change audio amplitude.

    Play Only Selected Frequencies When A Spectral Selection Exists

    Deselect this option to hear all frequencies in the same time range as a selection.

Change the vertical scale

In the Waveform Editor, you can change the amplitude or frequency scale of the vertical ruler.

Change the amplitude scale of the waveform display

  • In the waveform display, right-click the vertical ruler and select one of the following:

    Decibels

    Indicates amplitude on a decibel scale that ranges from –Infinity to zero dBFS.

    Percentage

    Indicates amplitude on a percentage scale that ranges from –100% to 100%.

    Sample Values

    Indicates amplitude on a scale that shows the range of data values supported by the current bit depth. (See Understanding bit depth.) 32-bit float values reflect the normalized scale below.

    Normalized Values

    Indicates amplitude on a normalized scale that ranges from –1 to 1.

Change the frequency scale of the spectral display

  • In the spectral display, right-click the vertical ruler and select one of the following:

    More Logarithmic or Linear

    Gradually displays frequencies in a more logarithmic scale (reflecting human hearing) or a more linear scale (making high frequencies more visually distinct).

    Note:

    Hold down Shift and roll the mouse wheel over the spectral display to show frequencies more logarithmically (up) or linearly (down).

    Full Logarithmic or Linear

    Displays frequencies completely logarithmically or linearly.

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