CSRE (The Canadian Speech Research Environment) is a comprehensive, microcomputer-based system designed to support speech research using IBM/AT-compatible micro-computers [4]. CSRE provides a powerful, low-cost facility in support of speech research, using mass-produced and widely-available hardware. The project is non-profit, and relies on the cooperation of researchers at a number of institutions. Work on the project is supported primarily by the fees generated when the software is distributed. Version 3.0 of CSRE has been used since 1989 by researchers in more than 100 laboratories in 12 countries. Version 4.0 offers a wider range of functions, runs faster, uses higher resolution displays, and supports additional hardware systems, including digital signal processing boards. Functions include speech capture, editing, and replay; several alternative spectral analysis procedures, with color and surface/3D displays; parameter extraction/tracking and tools to automate measurement and support data logging; alternative pitch-extraction systems; parametric speech (KLATT80) [7] and non-speech acoustic synthesis, with a variety of supporting productivity tools; and a comprehensive experiment generator, to support behavioral testing using a variety of common testing protocols.