1. The shirts can be hand washed after unplugging the transmitter (Do not machine wash).
2. if you put the transmitter on its most sensitive setting the shirt will light up when it hears a very soft noise or you can set the transmitter to its least sensitive setting which means it will take a lot of noise to make your shirt light up. The transmitter can either be charged by an adapter (included with purchase) or can be charged by 4 AAA batteries.