Audio Noise Reducer
Remove background noise from voice recordings online for free. Our audio noise reducer applies spectral subtraction to eliminate hiss, hum, fan noise, and ambient noise from any audio file. Upload your recording, adjust the strength, and download the cleaned audio as WAV. All processing runs locally in your browser — your audio never leaves your device. No signup required.
Upload a voice recording or audio file. Our noise reducer applies spectral subtraction to remove background hiss, hum, and ambient noise. All processing runs locally in your browser — your audio never leaves your device.
Drop your audio file here
or click to browse — MP3, WAV, M4A, OGG, WebM supported
The tool estimates the noise profile from the first ~0.2 seconds of audio (assumed to be noise-only silence). For best results, ensure your recording starts with a brief moment of background noise before speech begins.
- Start your recording with 0.5–1 second of silence (background noise only) before speaking
- Use Medium strength for voice recordings — Aggressive may introduce artifacts
- Works best on stationary noise (hiss, hum, fan noise) — not on music or variable noise
- Output is always WAV (lossless) — convert to MP3 separately if needed
Why Use Our Audio Noise Reducer?
Spectral Subtraction Algorithm
Our audio noise reducer uses spectral subtraction — the same technique used in professional audio software. It estimates the noise profile from the first frames of audio and subtracts it from the entire recording.
Adjustable Strength
Control how aggressively noise is removed with the strength slider. Light mode preserves more audio quality; Aggressive mode removes more noise but may introduce subtle artifacts on complex audio.
A/B Comparison
Play the original and processed audio side by side with the Play Original and Play Result buttons. Hear exactly how much noise was removed before downloading.
100% Private — No Uploads
All audio processing runs entirely in your browser using the Web Audio API. Your audio files are never uploaded to any server — complete privacy for sensitive voice recordings.
Common Use Cases for Audio Noise Reducer
Podcast & Interview Cleanup
Podcasters use our audio noise reducer to remove background hiss, HVAC hum, and room noise from voice recordings before publishing. Clean audio makes a significant difference in listener experience.
Voice Memo Improvement
Use our audio noise reducer to clean up voice memos recorded on a phone in noisy environments. Remove traffic noise, office chatter, and ambient hum to make speech clearer and more intelligible.
Video Voiceover Cleanup
Content creators use our audio noise reducer to clean up voiceover recordings before adding them to video. Remove microphone hiss and room noise without expensive audio editing software.
Online Meeting Recordings
Use our audio noise reducer to clean up recorded video calls and online meetings. Remove keyboard noise, fan hum, and background noise to make transcription and review easier.
Music Demo Cleanup
Musicians use our audio noise reducer to remove tape hiss and room noise from demo recordings. Improve the clarity of acoustic guitar, vocals, and other quiet instruments.
Archival Audio Restoration
Use our audio noise reducer to reduce hiss and hum from old recordings, cassette tapes, and archival audio. Improve intelligibility of historical recordings for transcription and preservation.
Understanding Audio Noise Reduction
What is Spectral Subtraction Noise Reduction?
Spectral subtraction is a classic audio noise reduction technique that works in the frequency domain. It estimates the noise profile — the average frequency spectrum of the background noise — from a section of audio assumed to contain only noise (typically the first few frames of silence before speech begins). It then subtracts this noise spectrum from every frame of the audio signal, leaving only the desired sound. Our audio noise reducer implements this algorithm entirely in your browser using the Web Audio API and a custom FFT implementation — no server required.
How Our Audio Noise Reducer Works
- Upload Your Audio: Drop or select any audio file (MP3, WAV, M4A, OGG, WebM). The file is decoded to raw PCM samples using the Web Audio API — entirely in your browser.
- Noise Profile Estimation: The tool analyzes the first ~0.2 seconds of audio (approximately 20 frames) to estimate the noise profile. This section should contain only background noise — no speech or music. The average frequency spectrum of these frames becomes the noise reference.
- Spectral Subtraction: Each frame of audio is transformed to the frequency domain using FFT. The noise spectrum is subtracted from the signal spectrum (scaled by the strength setting). The result is transformed back to the time domain using inverse FFT and reassembled using overlap-add reconstruction.
- Download the Result: The processed audio is encoded as a lossless WAV file and made available for playback and download. Compare the original and processed audio using the A/B playback buttons.
What the Noise Reducer Handles
- Stationary noise: Hiss, hum, fan noise, air conditioning, electrical buzz — noise that stays constant throughout the recording.
- Microphone self-noise: The inherent noise floor of budget microphones and phone recordings.
- Room ambience: Consistent room tone and reverb tails that appear in the noise profile.
- Tape hiss: The characteristic high-frequency noise from analog tape recordings.
Important Limitations
Spectral subtraction works best on stationary noise — noise that stays constant throughout the recording. It is less effective on variable noise (traffic, voices, music in the background) because the noise profile changes over time. Very aggressive settings may introduce musical noise — a metallic, warbling artifact caused by over-subtraction. If you hear artifacts, reduce the strength setting. The output is always WAV format — convert to MP3 separately if needed.
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Frequently Asked Questions About Audio Noise Reducer
An audio noise reducer removes background noise from audio recordings using signal processing algorithms. Our audio noise reducer uses spectral subtraction — it estimates the noise profile from the first frames of audio and subtracts it from the entire recording, running entirely in your browser.
Our audio noise reducer works best on stationary noise — hiss, hum, fan noise, air conditioning, electrical buzz, microphone self-noise, and tape hiss. It is less effective on variable noise like traffic, voices, or music in the background, because those change over time.
The tool estimates the noise profile from the first ~0.2 seconds of audio. This section should contain only background noise — no speech or music. If your recording starts immediately with speech, the noise profile will include speech frequencies and the result will be poor. Add a brief moment of silence at the start before speaking.
Yes. All audio processing runs entirely in your browser using the Web Audio API — your audio files are never uploaded to any server. Your recordings stay completely private on your device.
Yes, our audio noise reducer is 100% free with no signup, no account, no usage limits, and no advertisements.
Musical noise is a metallic, warbling artifact caused by over-subtraction — when the noise reduction removes too much of the signal. If you hear it, reduce the strength slider to Light or Medium. Musical noise is more common on recordings with low signal-to-noise ratio.
WAV is a lossless format that preserves the full quality of the processed audio. Converting to MP3 after noise reduction would add compression artifacts on top of the already-processed audio. Download the WAV and convert to MP3 separately if you need a smaller file size.
There is no artificial file size limit. Since all processing runs in your browser, the practical limit is your device's available RAM. Most modern browsers can handle audio files up to 50–100MB without issues.