Eartheater breaking real glass with her voice required research & rehearsal. Factors included glass temperature, size, shape, age, pitch & physical stamina. No special FX used: captured all in camera at 1000+ fps.
i've seen a few fellow feline therians asking for purring help, so here it is!
press the tip of your tongue to the inside of your front two bottom teeth and then slide it down until you can't anymore*. close your mouth almost all the way but leave at least a tiny opening or it won't work. make sure the back of your tongue is slightly touching the back of your upper pallet and breathe into your mouth. if it doesn't work or you want a different frequency of purr, try adjusting your tongue, changing how much of a gap you left between your lips**, or changing how hard your teeth are pressed together.
*how loud, quiet, chirpy, breathy, or growly your purr is mostly depends on how far down your tongue is. if you want a quieter, breathier purr try only bringing your tongue down half way. if you want a louder purr, bring it all the way down and even slide it as far back as you can.
**to get the gap size i've found works best, make small duck lips (?) and squeeze your teeth together. (this also clears congestion lmao)
the religious experience that is will branner's vocals in literal monster needs to be studied. like why am i transcending this plane every fucking time i hear it??