Are these Norton sounds?

Every so often, I'll get two sounds from my computer:

- a "bo-i-i-i-ng" sound, which would seem to indicate that something is wrong.

- after some time, what sounds like strumming a harp -- which would indicate that it's fixed.

These sounds aren't in System Sounds, and I have no idea where they're from.  Could they be associated with NIS?

Does anyone know?