Simulation 1

This simulation assumed that f₁(t) was an AM complex tone as shown in Fig. 8, where F₀(t)=200 Hz, N_F0=10, and the tone's instantaneous amplitude was sinusoidal (10 Hz), and that f₂(t) was bandpassed pink noise, having a bandwidth of about 6 kHz. Five types of f(t) were used as simulation stimuli, where the SNRs of f(t) ranged from 0 to 20 dB in 5-dB steps. The SNR shows the ratio of signal to noise in the concurrent time region.

For example, when the SNR of f(t) was 10 dB, as shown in Fig. 9, the proposed method could segregate A_k(t) with high accuracy and could extract $\hat{f}_1(t)$, shown in Fig. 10, from it. In this case, the precision for A_k(t) is shown in Fig. 11 (top panel). In addition, the average SDs of $\hat{f}_1(t)$ and f(t) for five simulations are shown in Fig. 11 (bottom panel). It was possible to improve the precision by about 7.3 dB and the spectrum distortion by about 17.6 dB as noise reduction, comparing the proposed method with condition 3. Hence, the proposed model could extract with high precision the amplitude information of signal f₁(t) from a noise-added signal f(t) in which the signal and noise were in the same frequency region.