I want you to make my headphones noise canceling!
Input
Sound from the default mic on the computer it is run on.
Output
The sound inverted and and volume halved via the default sound output.
Rules
Standard loopholes.
Winning:
Shortest delay from input to output.
I made a-ta.co/jelly with the intention of having all documentation there and easy to search, you can also type Ctrl-S, type a name or function of an atom, and press enter to insert it.
I've never used the input/output commands in my entire Jelly career; I've always used the implicit left/right arguments and implicit return value output.