Description of Spectral Subtraction Speech Enhancement Algorithm

This MATLAB code implements the spectral subtraction speech enhancement algorithm, a widely used speech signal processing technique for noise reduction and improving speech clarity and audibility. The algorithm operates based on Short-Time Fourier Transform (STFT) analysis and spectral difference calculations, where noise components are estimated and subtracted from the speech signal's frequency spectrum. The implementation typically involves frame-based processing with overlap-add reconstruction, utilizing magnitude spectrum subtraction while preserving phase information. Key MATLAB functions employed include stft for time-frequency analysis, spectral subtraction with noise estimation algorithms (such as minimum statistics or voice activity detection), and istft for signal reconstruction. The algorithm has proven effective in practical applications, significantly enhancing speech quality and intelligibility by reducing stationary noise components while minimizing speech distortion. For applications requiring speech enhancement, spectral subtraction provides a robust solution with relatively low computational complexity, making it suitable for real-time implementations. The code demonstrates proper parameter tuning for subtraction factors and noise floor constraints to balance between noise reduction and speech quality preservation.