Overview
No noise removal tool can fully recover a recording made in a loud room — prevention is always better than cure. But for steady background noise like air conditioning, fan hum, and computer noise, modern tools (including free ones) can remove it cleanly with minimal artefacts if used correctly.
What You Need
- Your noisy recording (WAV preferred)
- Audacity (free) for basic noise reduction
- Optional: NVIDIA RTX Voice, Krisp, or Adobe Podcast Enhance (free AI tools)
- Optional: iZotope RX Elements (~$99) for professional results
Steps
Identify the type of noise
Different noise types require different tools. Steady broadband noise (fan hum, air conditioning, tape hiss): Audacity noise reduction works well. Intermittent noise (traffic, keyboard clicks, dog barking): needs a noise gate or manual editing. Variable broadband noise (crowd noise, wind): requires AI tools or iZotope RX. Correct diagnosis prevents wasted time on the wrong approach.
Method 1: Audacity noise reduction (free)
Select a 1–2 second section of pure noise (no speech). Go to Effect → Noise Reduction → Get Noise Profile. Select your entire recording (Ctrl+A). Return to Effect → Noise Reduction and set: Noise Reduction 12dB, Sensitivity 6, Frequency Smoothing 3. Click OK. The critical setting is keeping Noise Reduction at 12dB or below — higher values remove more noise but introduce metallic "underwater" artefacts that are worse than the original noise.
Method 2: AI noise removal tools (free)
Adobe Podcast Enhance Speech (free at podcast.adobe.com/enhance) uploads your file and returns a cleaned version using AI. The results are often better than Audacity for mixed noise environments. NVIDIA RTX Voice (free, requires RTX GPU) runs in real time during recording. Krisp has a free tier with monthly minutes. These tools are dramatically easier than manual processing for challenging recordings.
Method 3: iZotope RX Voice De-noise (paid)
iZotope RX is the industry standard for audio repair. Load your file in RX Standalone, apply the Voice De-noise module in Adaptive mode — it continuously learns the noise floor and removes it even as it changes. The result is transparent on steady noise and handles variable noise better than any other tool at the price point. RX Elements (~$99) includes Voice De-noise.
Check for artefacts and adjust
After processing, listen critically on headphones to the transitions between silence and speech. Listen for: metallic resonance on vowels ("underwater" sound), warbling on sustained notes, musical noise (tonal artefacts that weren't there before). If you hear any of these, reduce the noise reduction amount. A slightly noisy but natural recording is always preferable to an artefact-filled "clean" one.
Pro Tips
- A noise gate (silences audio below a threshold) combined with light noise reduction is often more natural than heavy noise reduction alone.
- Always work on a copy of the original file — noise reduction is destructive and can't be undone without re-processing.
- Use our Noise Floor Calculator to understand how SNR affects your recording quality before you reach for noise removal.