Let me set the scene: you’re in the bathroom getting ready, or you’re washing dishes in the kitchen, or you’re folding clothes in the laundry room. You’re bored and you want tunes, but you don’t want to crank the speakers in the living room/you don’t have space to use your laptop/you’re afraid you’ll spill on it. You’re stuck listening to headphones which can be inconvenient or doing without entirely, right? Nah.
Check it: place your phone into a bowl and you have instant acoustic amplification. As you can see, I don’t even have the volume cranked. This saves battery, and the sound is louder and richer. SCIENCE.