@Bark3N has mentioned this before and it's the same for me...

The Heirloom on Wraith makes a sound that most people don't hear. But it's a static noise akin to white noise. Whether this is a feature of the kunai because it's wrapped in energy, or a bug, I have no idea.

This happens when you holster to run with the kunai out.

As someone with synesthesia, it is a constant white blur (a bit like old TVs) in front of my vision when I hear the noise. I hope there's an option in the future to disable the sound effect (if it's not intended, plz fix).