The phrase "crinkle noise" refers to the sound made when something is being crushed or crumpled, typically producing a rustling or crackling sound. Full definition
Munch Mitts aren't just for teething, but for sensory learning, too; the mitt features sensory stimulating crinkle noise throughout mitt, and is interchangeable between hands. (blog.guguguru.com)
Many rattles also have other textures that provide sounds like crinkling noises. (thespruce.com)
It even makes a sensory - stimulating crinkle noise while she chews! (momtricks.com)