Audio Compression Techniques for Clearer Dialogue in Book Trailers

Audio compression reduces the dynamic range of an audio signal. Simply put, it lowers the volume of the loudest parts and raises the quieter ones — making the voiceover more consistent and easier to understand, especially when layered with background music or effects.

🛠️ Techniques You Can Use as a Book Trailer Maker:

Set a Proper Threshold

The threshold is the volume level at which compression kicks in. For voiceovers, set it around -18 dB to -12 dB so that peaks in loud dialogue are smoothed without squashing everything.

Ratio Matters

A good starting point is a 3:1 or 4:1 compression ratio. This ensures aggressive peaks are tamed without making the voice sound robotic.

Attack and Release Settings

Fast attack (1–10 ms) catches quick spikes like "p" and "t" sounds.

Medium release (50–200 ms) helps preserve a natural decay in speech.

Avoid overly fast settings or the speech may lose its clarity and emotion.

Use a Limiter After Compression

After applying compression, add a limiter to ensure the audio doesn’t clip when mastered with background music or SFX. It adds that polished, broadcast-quality feel to the book trailer.

Sidechain the Music

For professional-level book trailers, sidechain compression can duck the background music slightly when the voiceover speaks — commonly used in film and advertising. This keeps the dialogue clean and upfront without having to lower the music volume overall.

🎙️ Real Talk from a Book Trailer Maker

As a book trailer maker, I’ve seen authors struggle with audio levels more than any other part. One client had a breathtaking visual trailer but recorded their VO on a basic laptop mic. The background score overpowered every line. After applying light EQ, compression, and sidechaining the music in Adobe Audition, the transformation was night and day. The story was finally heard, not just seen.