Digital Signal Processing Lab

Noise Removal from Audio using Fourier Transform

Upload an audio file, inspect its waveform and frequency content, then reduce noise by filtering Fourier coefficients and reconstructing a cleaner signal directly in the browser.

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1. Upload Audio

Select a `.wav` or `.mp3` file to begin analysis.

Built-in sample: sample-audio.wav

2. Original Signal Graph

Time-domain waveform of the uploaded signal.

3. Frequency Spectrum

Magnitude vs frequency after applying the Fourier Transform.

4. Noise Filter Controls

Adjust filtering strength and choose a preset response.

12% Removes small-magnitude frequencies below the selected level.

How it works

Fourier Transform separates the audio into frequency components. Filtering removes unwanted coefficients, and the Inverse Fourier Transform converts the modified spectrum back to a cleaner time signal.

5. Cleaned Output

Listen to the reconstructed audio after noise reduction.

Before vs After Comparison

Overlay of original and cleaned waveforms.

Bonus: Spectrogram

Short-time frequency view of the original audio.