In general, IDE CDs are not good choices for audio. This is especially true of the old versions of EZ CD Creator. Loading the PC's bus and CPU To make a CD up to 650MB of data must be pushed from one source to the CD writer. So don't even try to add info from a floppy directly. While the CD writes the data stream can't be disrupted, at least not for very long.
All systems have some disturbances, however.
Even if you don't launch a huge, new application, the mouse gets moved or a screen saver might kick in, for example. Some setups can't even take the extra load of a screen saver. It is standard procedure to disable all screen savers while burning CDs. These programs do take a lot of CPU cycles to keep complex, changing shapes whizzing around your screen. Most CD writing software will either ask the user to disable or will automatically disable WIN95's Auto Insert Notification.