title: stop all sounds in Web Audio API
body: <p>I loaded and played multiple sounds with web audio api at the same time. Is there any way to stop all sounds? </p>
  
  <p>ex: a button to stop all sounds now.</p>
  
  <p>Since I have more than 10 sounds playing at the same time, I dont wanna manually use noteOff(0) (or stop(0) ) for each sound source.</p>