Hi,

That is a known rendering bug in CapCut's audio processing engine.

When adjusting the Timbre filter, CapCut applies an EQ curve that accidentally boosts ultra-high harmonic frequencies often creating a high-pitched "mosquito" whine or static artifact across the track.

Because the engine processes audio uniformly, it locks that high-pitch hum into the whole clip instead of cleanly modulating the tone.

Try these practical workarounds to fix or bypass the issue depending on your workflow:

Workarounds to Fix the Noise

Method 1: The "Denoise First" Chain (Quickest Fix)

CapCut’s built-in noise reduction can clean up the artifact, but sequence matters.

1. Adjust your Timbre setting to the tone you want.

2. Scroll down in the Audio panel on the right (or bottom menu on mobile) and toggle Reduce Noise / Noise Reduction.

3. If the high pitch is still there, export the audio track separately (or duplicate and export the video clip as audio), re-import it, and run Reduce Noise on the fresh track.

Method 2: Alternate Effect (Voice Enhancer)

If you are tweaking Timbre to make a voice sound deeper or warmer, use the Pitch slider or Voice Enhancer instead of Timbre:

• For depth/warmth: Go to Audio → Speed tab → toggle Pitch slightly down. It avoids the harsh EQ bump that triggers the noise bug.

• For clarity: Use CapCut's Enhance Voice feature instead of adjusting treble/timbre manually.

Method 3: Clear Cache & Reset CapCut Audio Engine

Sometimes local temporary audio rendering files get corrupt and keep compounding audio glitches.

• On Desktop: Click Settings (gear icon) → Cache → Clear Cache, then restart CapCut.

• On Mobile: Go to Settings in CapCut home screen → Clear Cache → restart app.

• Pro Tip: If you're on CapCut Desktop and need precise control, do your main EQ adjustments using a free dedicated audio app like Audacity or BandLab, export the WAV file, and drop it back onto your CapCut timeline. CapCut's native audio filters are prone to clipping/artifacts when pushed too hard.