On After Effects, you can control effects, such as a text glow effect, to react to audio tracks.
To get started, add a Glow effect to your text layer (Effect > Stylize > Glow) and set it how you desire. Then, ensure an audio track is in your composition.
Next, right-click on your audio track and select “Keyframe Assistant Convert Audio to Keyframes.” This creates a new layer called “Audio Amplitude,” which houses your keyframes. In this example, you’ll just need to reference the keyframes under Both Channels. You want these keyframes to manipulate Glow Threshold, so set akeyframe by alt-clicking or opt-clicking on the stopwatch.
An expression for Glow Theshold appears. Pickwhip from there to the “Audio Amplitude Both Channels Slider.” If you play the timeline now, the inverse is happening. You see the glow when there are low sounds versus the louder sounds. This is because Glow Threshold shows more glow when the value is lower, not higher.
To fix this, find what the value of the slider is at a peak audio wave. In this example, it is about 17 or 18. So, alter the expression to get a value near this. Here, if you type in 30 and subtract the rest of the expression… 30-17 will give us 13, which is a perfect Glow Threshold value to show the glow wanted in this instance.
Check out this short After Effects tutorial video:
