[Note before: This plugin is listed as "No longer available" but it is in fact still available through the developer's website].
With this plugin you can add short chunks of beeps (either of the same tone or various -> "Variation" parameter), white noise or muted breaks to your audio.
The beeps do what they should, but don't sound very pleasant. White noise comes in and goes out abruptly.
I think the most useful mode of this device is just using muted breaks, of which you can even set the volume of with the "Gain" parameter.
Downsides:
1. The protecting noises only can stay for a maximum of 1,5 second and work dependent upon a regular interval in time. There is no option you can create a long and persisting protector noise.
2. The sound chunks of 1,5 sec come in with no fade-in or fade-out, which can really be annoying to listen to. Especially when you want that your protector sounds are noticable loud. Here a fade-in and fade-out could have build a way easier and pleasant transition.
This plugin belongs to a niche of plugins and is even in the niche a very unique thing. I don't want to disregard it to much, so I still give 4 stars, but I doubt it can be really helpful even for its own purpose.