Work in progress - teaching speech signal processing and coding using LabVIEWTM

This paper presents a visual programming and visualization tool for use in covering signal processing aspects of speech coding in a DSP class. The tool is based on the national instruments LabVIEWtrade environment. The framework of this tool was built using existing C code as a library along with LabVIEW´s native functionalities. Standardized linear predictive coding algorithms have been implemented; these are used to demonstrate in our DSP classes how digital filters and signal modeling is utilized in cellular and military communications. Experiments covered include the introduction of speech synthesis models, parameterization of speech in terms of filter and excitation parameters, and robustness of speech parameters to additive and channel noise. The tool provides capabilities for both quantitative and subjective assessment of the synthesized speech signal. An assessment process for the tool is in place and preliminary results will be presented at the conference.