Background noise is the number one thing that makes otherwise great voiceovers, podcast interviews, and lecture recordings sound unprofessional. Whether it is a whirring computer cooling fan, air conditioning rumble, or electrical buzzing, cleaning your audio makes an immediate difference.
The Two Types of Background Noise
Before adjusting any sliders, identify what kind of noise you are dealing with:
- Continuous Steady Noise (Fans, AC, Mic Hiss) — This noise stays at a constant volume and frequency throughout the recording. Modern spectral noise reduction removes this effortlessly while keeping voices crisp.
- Sudden Intermittent Noise (Door Slams, Keyboard Clicks, Dog Barks) — These are sudden spikes. For these, it is best to use an Audio Cutter to trim out silent pauses between speech segments.
The 30% Sweet Spot for Noise Reduction
The most common beginner mistake is cranking noise reduction to 100%. Aggressive denoising strips high-frequency consonants (the crisp 'S', 'T', and 'K' sounds), making speech sound muffled, metallic, or underwater.
Instead, set the reduction slider to 25%–35%. This moderate pass eliminates 80%+ of steady background hiss while keeping the human voice completely natural, warm, and intelligible.
Fixing 50Hz and 60Hz Electrical Ground Hum
If your microphone cable or laptop charger produces a steady low-frequency electrical drone, use the 10-band equalizer to notch down the 60 Hz slider (in North America) or 50 Hz slider (in Europe and Asia) by -6 dB. This instantly eliminates line hum without touching vocal warmth.
Always record 3 to 5 seconds of complete silence at the beginning of your recording session. This gives you a clean sample of room tone to check background levels.