Vague Web Audio API Guidelines

Webpage should also only play sounds in response to user interaction

Background music and other sound can be safely implemented by informing the user that the program uses sound, and ask if they would like to implement it. Upon confirming / denying, store this somewhere and only apply sound when necessary. This is not a loophole, and has been practiced before with no negative consequence.

Webpages should not play sounds immediately upon load.

You cannot start playing the background music after a delay, as this is contrary to the rule referenced above. Your comment about user interaction is also detailed above.

...and should not loop sounds endlessly

I believe this is intentionally only added to PJS, since most developers working in the HTML environment are mature enough to understand not to blast someone's ear out endlessly. It seems to be targeted at the beginner programmers looking to make "troll" programs.

Bear in mind, the guidelines were likely written assuming a user with malicious intent. While not optimal for most users adhering to the rules, it certainly helps maintain a safe learning environment.

As a general suggestion to the guidelines, use common sense. Offer solutions to support users who made a mistake (i.e. clicked "Use Sound" on accident) and generally do what you think Khan Academy would like you to do.

https://www.khanacademy.org/computer-programming/contest-music/4542789552062464

> Can I loop sounds but then have the user stop it and start it?

"Yes, as long as the sounds do not start playing as soon as the program loads and you clearly indicate how the user can start/stop the sounds." - Evan Lewis

> If we're using HTML/JS, can we use sine oscillators to create real music that is supported on Khan Academy?

"You're welcome to use getSound() to add sounds to your project, but beyond that those are the only sounds that are currently allowed to be used." - Evan Lewis

Later: "We did, however, update the webpage guidelines several weeks ago to say "Webpages should only create sounds using the files available to ProcessingJS programs or the Web Audio API oscillator."

So, my answer above is now outdated. You can use oscillators in the webpage programs to create custom sounds, assuming it follows the other rules on sounds and doesn't reproduce any copyrighted music" - Evan Lewis

> 1. I see that Squishy's music maker was unhidden. Does that mean that oscillators are now allowed in both pjs pages and webpages?
> 2. With music now being allowed, how should the guideline about not looping sounds endlessly work? Does this rule prevent music from being used in the background for games, as that requires looping?
"1. Technically the PJS programs should only use the sounds listed in the sound-picker, since that's what the guidelines state. However, using the Web Audio API in the PJS programs would just result in the program being hidden from the Hot List for accessing externals.

2. As long as there's a way to mute/stop the sounds, or at least a warning that continuous sounds will play after some sort of user interaction, it should be fine. Basically, just don't be annoying with it and there shouldn't be any issues." - Evan Lewis