Visual Editing in the Spectral Frequency Display

The Spectral Frequency Display in Adobe Audition is beautiful to look at, to be sure. But it gives you insight into your audio clips that a waveform view can’t match. For example, in the Spectral Frequency Display, you can see individual harmonics and overtones, and their relative strength. You can see noise. Best of all, you can edit what you see using graphic editing tools with which you’re probably already familiar, and make edits to your audio with near-surgical precision.
If you’re dazzled by brilliant colors, you might miss some of the more useful tools offered by the Spectral Frequency Display. While in the Waveform Editor, let’s take a look at several different types of sound in the Spectral Frequency Display. Frequencies are displayed from low at the bottom to high at the top, and in all cases, the yellower the color, the louder the sound.

Example 1. Here are seven different sounds, as seen in the Spectral Frequency Display. The frequencies along the vertical ruler on the right are in linear mode. It seems that most of the loud frequencies are very small, down at the bottom, and probably difficult to edit. Click on the screen shot for a larger view of it.

Example 1. Here are seven different sounds, as seen in the Spectral Frequency Display. The frequencies along the vertical ruler on the right are in linear mode. It seems that most of the loud frequencies are very small, down at the bottom, and probably difficult to edit. Click on the screen shot for a larger view of it.

If you wanted to zoom in on those lower frequencies in order to edit them, you certainly could. But there’s a more powerful tool available to help you with this. Option-click (Mac) or right-click (PC) in the vertical ruler on the right, and the following menu appears. From this menu you can configure the vertical scale of frequencies from all linear to all logarithmic, which will make the lower frequencies much more visible. You can also adjust the resolution, to make the Spectral Display more precise.

Example 2. Option-click or right-click in the vertical ruler to bring up this menu. Settings such as More Logarithmic and Full Logarithmic will make the lower frequencies more easily visible. Increasing Spectral Resolution makes individual harmonics within a sound easier to see.

Example 2. Option-click or right-click in the vertical ruler to bring up this menu. Settings such as More Logarithmic and Full Logarithmic will make the lower frequencies more easily visible. Increasing Spectral Resolution makes individual harmonics within a sound easier to see.

The following screen shot shows the exact same audio file as in Example 1, but with Full Logarithmic selected as the scale in the vertical ruler. Note the huge difference in the appearance of the loudest sounds, which for the most part includes the fundamental pitch of an instrument or voice, or the main element in noise. Much more information about these particular sounds is revealed when the scale is logarithmic: You can see the individual notes of the bass in the power trio, the dialogue, and the tuba. You can see the Doppler effect of a passing jet in the airport taxiway. In all cases, you can clearly see frequencies even below the fundamentals.

Example 3. This is the same audio clip as in Example 1, with frequency set to logarithmic scale. The individual notes and harmonics are much more visible. It's as if the audio clip has just given up all its secrets! Click to view a larger version.

Example 3. This is the same audio clip as in Example 1, with frequency set to logarithmic scale. The individual notes and harmonics are much more visible. It's as if the audio clip has just given up all its secrets! Click to view a larger version.

With the logarithmic setting, most of the sounds that concern audio editors stand out in relief: fundamentals, overtones, and even noise. The Marquee Selection tool, Lasso Selection tool, Paintbrush Selection tool, and Spot Healing Brush tool are very easy to use and are uniformly effective with all of these sonic elements. But there are a couple of other tools that come up in a contextual menu when you option-click or right-click on the Spectral view itself, such as Capture Noise Print (the first step to automatically removing noise from a clip) and Auto Heal Selection (dramatically reduces a particular sound or noise without eliminating the surrounding background ambience).

Example 4. Option-click or right-click in the Spectral Display iteslf, and this menu appears. Click for a larger view.

Example 4. Option-click or right-click in the Spectral Display iteslf, and this menu appears. Click for a larger view.

The copy command works just as you’d think, letting you make a copy of any area you can select. What do you do with copies of audio data? Do some sound design by pasting part of one sound into another, for one thing. In the following screen shot, we copied the approaching police siren on the left (the oscillating pitch of which is highly), and then pasted it onto the dialogue clip. The result: A dialogue with a passing siren, but without the whoosh of the tires and body noise.

Example 5. Copy and paste in the Spectral Frequency Display works just as it does in any image editing program, such as Adobe Photoshop. But in this case, it takes only the frequencies that you select, and blends the associated sounds as well as the images upon pasting. Here we've copied the sound of an approaching police siren on the left, and pasted it onto the dialogue clip on the right.

Example 5. Copy and paste in the Spectral Frequency Display works just as it does in any image editing program, such as Adobe Photoshop. But in this case, it takes only the frequencies that you select, and blends the associated sounds as well as the images upon pasting. Here we've copied the sound of an approaching police siren on the left, and pasted it onto the dialogue clip on the right.

You can make even more precise selections with the Lasso Selection or Paintbrush Selection tools. In the following screen shot we use the Lasso Selection tool to select and delete the annoying squeak of a shutting door without disturbing the shutting sound. The result: a door that shuts without squeaking.


To learn more about the power of the Spectral Frequency Display, watch Jason Levine’s excellent video demo by clicking on this link.

Comments are closed.