iOS xcode microphone volume detection?

What frameworks are required to detect how loud someone is talking into a microphone开发者_如何学C... Also, can anyone tell me what to search for in the documentation or google so I can create some code... What line of code would be commonly used when detecting volume levels of noise through the microphone? Thanks!

This seems to be a duplicate of:

Realtime microphone sound level monitoring

However, that question is old and the accepted answer links to a deprecated library. They now recommend that you instead use AVAudioRecorder. They suggest this tutorial and it seems to be what you are looking for.