Working with iPhone microphone programmatically

I'm developing an iPhone 3.1 application.

I want control by voice a text. If a person blows over microphone, the text will appear. If that person is blowing strong the text will appear quickly, but if he is faintly blowing the tex开发者_C百科t will appear slowly.

I want to control if there is a sound over microphone, and the volume (high or low).

Is that possible?

Is this of any use?

A simple class for listening to microphone levels, suitable for the iPhone.

Here is the link: https://github.com/stephencelis/sc_listener