REMOVING NOISE FROM AUDIO AND VIDEO

Sometimes the most effective method to get rid of background noise is to lower the volume. Low-level noise often sits at the “floor” of the audio, at the lowest volume levels. Lowering the overall volume pushes the volume of the noise below the floor. If you’ve recorded a good, strong voice signal which is much louder than any background noise, like we mentioned above, you may end up with a clean voice and no noise.

In VEGAS Pro, you can lower the volume of an audio event in a few different ways.

✓ Slide the volume slider in the track header to the left to lower the volume of all audio events in that track. To lower the volume of a single event, click the top of the event and drag the Gain level down.

But sometimes simply lowering the volume doesn’t work, because the volume of the noise is too close to the volume of the voice and the voice volume becomes too low.  If your background noise is something like a constant hiss, it may be a job for the Noise Gate. The Noise Gate eliminates any sound below a certain volume level, so if the noise volume is always lower than the sound you want to keep, the Noise Gate solves the problem.

✓ Click the Track FX button in the track header. The Audio Track FX window opens.

✓ Click Noise Gate. The Noise Gate controls appear.

✓ Raise the Threshold level slider, which sets a threshold volume level. The Noise Gate eliminates all sound below that volume level.

The drawback is that the sounds you want to keep, especially the human voice, vary in volume, so there may be parts of sounds you want which get caught in the Noise Gate and are eliminated along with the noise.

✓ Play the clip. If you hear bits and pieces of the audio cutting out, then adjust the Attack Time and Release Time sliders. These sliders control how aggressive the Noise Gate is, so increasing the Attack Time and Release Time may help restore some of the wanted sound.

✓ Adjust to find a balance between eliminating the noise and restoring the sounds you want.

When all else fails, you can try to cover the unwanted sounds with music or other sounds. If you create a robust sound field, you can often make the unwanted noise less noticeable.

VEGAS Pro 18 comes equipped with a brand new FX plug in, Denoise. Denoise analyzes the video and mitigates noise as best as it can while trying to preserve detail.

✓ Drag the Default Denoise preset from the Video FX window and drop it on your video event. The Video Event FX window opens, and the Denoise controls appear.

✓ Under Noise Reduction, adjust the Chrominance and Luminance sliders until you eliminate the noise to your satisfaction. Keep in mind, noise changes as the image changes, so it sometimes helps to loop your video and play it back over and over while you work.

✓ Double-click the event and click Loop Playback, then click Play. Adjust Chrominance and Luminance on the fly. You can also keyframe the effect to make fine adjustments to different sections of the video.

The cost of denoising video is usually sharpness. When you denoise, you basically blur the picture to take the edge enhancement off your noise. But when you do, you blur everything else in the image, too. While you won’t end up with a blurred image like you’d have if you added a blur effect, you may see unnatural skin or facial features which look somewhat like an oil painting. In any case, you’ll lose detail.

You can bring back some of that detail. 

✓ Under Sharpening, adjust the Amount slider to the right to apply sharpening. Too much will bring back some noise or have other unwanted effects, so use only as much as you need.

As we said above, most video noise comes about because there’s not enough light. Naturally, most noise is found in the darker areas of video, but not in the blackest areas, because black noise against a black image isn’t visible. Darken those areas even further, making those areas all black or close to all black, and you can eliminate a lot of the noise.

✓ Click the video event. Click the Color Grading button in the timeline toolbar. The Color Grading panel opens.

✓ On the Color Curves tab, enable Brightness and disable Red, Green, and Blue.

✓ Grab the handle at the lower left of the white line in the Color Curves graph and drag it down, lowering the brightness of the darkest areas of the image.

✓ Flatten the curve down to push all of that area of brightness to black. Adjust the curve area you flatten to restore wanted detail you may have lost. As with other solutions we’ve discussed, it’s a balancing act between eliminating noise you don’t want and keeping details you do. Find a balance that’s acceptable to you.