Frequency Domain Processing of Speech Signals
Speech signals, though time-varying and non-stationary stochastic processes, can be approximated as stationary over short time intervals. Speech enhancement can be achieved by estimating the short-time spectrum of "clean" speech from the noisy speech spectrum. Since noise is also a stochastic process, this estimation must be based on statistical models. Leveraging human auditory perception's insensitivity to phase in speech spectral components, these enhancement algorithms primarily focus on short-time spectral magnitude estimation, often implemented using techniques like the Fast Fourier Transform (FFT) for efficient frequency analysis.