Figure 3
From: Contribution of statistical tests to sparseness-based blind source separation
Effect of noise on sparse signals. (a) Noiseless audio signal mixture in the time–frequency domain. Many time–frequency coefficients are close to 0. (b) Noisy audio signal mixture in the time–frequency domain. The time–frequency coefficients with small amplitudes are masked by noise. Only big time–frequency coefficients remain visible. They are not really affected by noise as long as the signal to noise ratio is large enough. The proportion of these significant coefficients is less than one half.