You can use the audio subsystem to:
Each of these require to use the SCO play and record utilities (or others of your choice). If you use vplay(1) or vrec(1), you must always have a command line prompt available to control recording and playback; scosound(X1) is a graphical utility and more appropriate for real-time control. You may also find it helpful to have a command line prompt available to set and test initial levels with mixer(1), or you can use another mixing program, such as xmmixer from SCO Skunkware.