The following Matlab project contains the source code and Matlab examples used for speech oscilloscope. http://simulations.narod.ru/ The program continuously listens microphone and plot signal waveform. Position of maximum is used for synchronization. This can be useful in speech recognition research. See how it works here: http://www.youtube.com/watch?v=jz4Rp71weYo run run_me.m and say sounds like "aaa" "eee" to the microphone.
The source code and files included in this project are listed in the project files section, please make sure whether the listed source code meet your needs there.