A neural network for blind identification of speech transmission index

A hybrid neural network model is proposed to determine the speech transmission index of a transmission channel from transmitted speech signals without resort to prior knowledge of original speech. It comprises a Hilbert transform pre-processor, a PCA network for speech feature extraction and a multilayer back-propagation network for nonlinear mapping and case generalization. The developed method utilizes naturally occurring speech signals as probe stimuli, reduces measurement channels from two to one and hence facilitates speech transmission channel assessments under in-use conditions.