How to Remove Background Noise From Audio Recordings

Background noise is the enemy of professional audio. A podcast recorded in a room with an air conditioner, a voiceover with computer fan noise, a business call with traffic in the background — these are common situations that produce recordings people are embarrassed to use. Professional noise removal used to require expensive software like Adobe Audition or iZotope RX. Server-side processing makes it accessible to anyone.

Types of Audio Noise

Understanding what type of noise is in your recording helps set realistic expectations for removal:

Constant Noise (Easiest to Remove)

Constant noise maintains the same frequency profile throughout the recording. Air conditioning hum, computer fan noise, fluorescent light buzz, and tape hiss are all constant noise. This is the easiest category to remove because noise reduction algorithms can sample the noise profile and subtract it from the entire recording.

Variable Noise (Moderately Difficult)

Variable noise changes over time — traffic sounds, distant conversations, HVAC systems that cycle on and off. These require more aggressive noise reduction settings and may leave some artefacts.

Impulsive Noise (Hardest to Remove)

Sudden sounds — a door slamming, a phone ringing, a cough — are impulsive noise. These cannot be removed by standard noise reduction and require separate click/pop removal tools or manual editing.

How Noise Reduction Works

FlipFiles Pro uses the noisereduce Python library, which implements spectral noise gating — a professional technique used in recording studios. The process works in two stages:

1. Noise profiling: A sample of the audio containing only noise (typically the first 0.5 seconds, before speech begins) is analysed to build a frequency profile of the background noise
2. Noise subtraction: The noise profile is subtracted from the entire recording in the frequency domain, leaving only the signal that does not match the noise profile

The key parameter is the proportion decrease — how aggressively to reduce the noise. FlipFiles Pro offers three levels: light (0.5), medium (0.75), and strong (0.95). Higher levels remove more noise but can introduce audio artefacts if overused.

Audio Normalisation — Companion Tool

After removing noise, audio normalisation is typically the next step. Normalisation adjusts the overall volume of a recording to a target loudness standard. FlipFiles Pro uses EBU R128 loudness normalisation — the same standard used by YouTube, Spotify, and broadcast television.

Target levels by platform:

• YouTube: -14 LUFS
• Spotify / Apple Music: -14 LUFS
• Podcast (standard): -16 LUFS
• Broadcast / TV: -23 LUFS

Uploading content at the correct loudness level prevents YouTube from automatically turning down your video (making it quieter than competitors) and ensures your podcast sounds consistent with professional shows on the same platform.

Common Workflow: Podcast Episode Processing

1. Record your podcast episode (ensure 1 second of silence at start)
2. Upload to FlipFiles Pro → Audio Tools → Noise Remover (select Medium strength)
3. Download cleaned audio
4. Upload cleaned audio → Audio Normaliser (select -16 LUFS podcast standard)
5. Final audio ready for your podcast host

Total time with FlipFiles Pro: approximately 3-5 minutes per episode. The same workflow in Adobe Audition requires software expertise and 15-20 minutes of manual work.