In animation, actions often need to line up with sound, and seeing a waveform gives you visual hints without scrubbing audio over and over. Blender can show waveforms on sequencer strips natively, but that takes screen space and setup time. Sound Waveform Display puts the waveform directly inside the animation editor instead.
The main controls are straightforward: On enables or refreshes the display, Off disables it, and Height offset lets you tweak peak heights when they read too small or too high. You can source waveforms from the sequencer (the default) or from a speaker. With the sequencer, you can limit the view to selected strips, sound listed in the panel, audible strips, or audio within the scene range. Preferences add a customizable waveform color, a detail level ranging from Blocky up to High, and a verbose console option for debugging.
The addon requires FFmpeg, and its preferences explain how to obtain it, including an automatic download and install method. Waveform generation runs slowly, so it suits short ranges from a few seconds up to about a minute. It works with Blender 3.3 through 5.0 under a GPL license, and a demo video is available.