Experimental evaluation of different approaches to the multi-pulse coder

We report on the results obtained from simulations of the Multi-Pulse Excitation Coder as proposed by Atal and Remde [4]. We investigated the effects of the different analysis parameters on the resulting synthetic speech signals, using objective and subjective tests. We compared the in [4] proposed sub-optimal solutions with another sub-optimal solution based on an orthogonalization of the solution space and found that the original proposed solutions are reasonable choices. We demonstrate that the inclusion of a pitch detector significantly improves the perceived quality of the synthetic speech. We also describe a modification of the original algorithm, resulting in a lower complexity, and a speech quality close to the results obtained with the original algorithm.