Sing, Scream, Practice Anywhere — Portable Vocal Dampener Mask (KK1464) New November 2016 The rating is applicable for

The rating is applicable for hard materials such as rubberized sound barriers

so the room sounds tighter and recordings sound cleaner

Most diffusers won't show you the numbers

It also applies to a much lesser degree to softer materials like mineral fiber

Sing, Scream, Practice Anywhere — Portable Vocal Dampener Mask (KK1464) New November 2016 The rating is applicable forSing or scream anywhere without an apology The Arrowzoom KK1464 Vocal Dampener is a portable, soft foam mask built for singers, vocal coaches, voiceover artists, and anyone who needs to warm up, belt, or scream sing without rattling the walls. Slip it on, pop in the ear tubes, and rehearse in an apartment, dorm, hotel room, or backstage corridor without earning a noise complaint. Cup and tube design absorbs vocal output before it leaks into the room