A pitch extraction system based on phase locked loops and consensus decision

In this work a very low error rate pitch estimation system is presented, which is also very robust against noise. Two key aspects of the system are mainly responsible of such good behavior: on the one hand we use a multiple estimation scheme based on PLL’s. These devices provide us with robust information about the period of the speech signal harmonics. By combining this information with an additional independent estimation it is possible to obtain a robust estimation of f0. On the other hand, multiple estimations are combined in a stage that assesses each of them, retaining the more reliable ones. A final agreement value between these qualified estimations is the final result of the system. This consensus decision significantly improves the initial estimation accuracy. Overall performance is assessed by comparing our system to the get f0 algorithm, under clean and noisy conditions. We show that our system outperforms get f0 over all presented conditions.