How can I take audio input from user in a program

Question

Also pls tell how to make the program do function after getting audio input

Answer can be in any language
I will start learning the language that does so
Please tell

Answer 1

For JS, the AudioBuffer API

Answer 2

I couldn't understand
Pls explain a bit
I am learning JS and I have completed 50% coarse but this audiobuffer API thing wasn't mentioned