Basis Pursuit Decomposition: An Analysis of Spanish Words

Time-frequency representations (TF) of speech signals are commonly used to visualize the dynamic behavior. However the choice of the basis functions employed in the TF has an important effect on the number of nonzero coefficients occurring in the representation of the signal. Signals with different morphologies, such as vowels or fricatives, could benefit from the use of different bases for each of their representations. Different methods, such as matching and basis pursuit (bp), have been introduced to find representations of signals using combined bases. One drawback of these techniques is that the computational demands and computing times are liable to be far greater than those of more traditional methods. The present paper analyzes the performance of bp applied to Spanish words. In particular, early stopping times and their relationship to the number of coefficients found are studied. The quality of the reconstructed signals is also considered both quantitatively and qualitatively.