Review on Sony WF-1000XM3 Black Truly Wireless Earbuds with Mic, up to 32 Hours Battery Life, Stable Bluetooth Connection, Wearing Detection and Alexa Built-in for Noise Cancelling by Kiril Tilkov ᠌

"working time 8-9 hours" refers to continuous use with case recharges. They have a about 2-hour run time on a single battery. Even the shortest flight would require more than this. There are occasions when more sound is required. There was a note made saying that the case is closed. Even though I carried it in a backpack and pockets with cash, I didn't notice anything fishy after using it for six months. It always starts up in noise reduction mode, thus to turn it off, you have to switch it every time. The instructions for using the headset are useless. The other person keeps asking you to repeat yourself.