Homemade Sensory: the foil box

Sometimes, just sometimes, the hubby (Danny) comes up with some great ideas for the boys. Sensory play is usually my area of expertise, and the rough and tumble is his. But I've noticed that he's getting more and more into sensory play as Zack gets older. Because he now works from home full time, he gets to see Zack more often than he saw Joey at this age. He's remembering that whilst baby's are hard work during these early months, they can still be fun (I mean, that's so hard to remember on your 5th 5am wake up of the week!).
We've discovered that Zack, who is now 10 weeks old, absolutely adores the foil blanket and the noise of it rustling soothes him when he's upset - we've got a stray crisp packet one evening to thank for that inspiration! My best guess is that the noise is similar to white noise, even though Zack doesn't respond to white noise playlists...