Detecting sound in iphone

Can anyone tell me how to detect a sound on iphone....

Please help....please provide any s开发者_如何学JAVAource code or link if possible

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You can use AVAudioRecorder

http://mobileorchard.com/tutorial-detecting-when-a-user-blows-into-the-mic/

That tutorial works for any sound really... it goes through the steps of creating a high-pass filter to try and only detect blowing. You can change the values to make it more sensitive to sound or less sensitive.