title: get the sound level in decibels using objective-c
body: <p>I am new to iOS world . I have a doubt . I would like to achieve the dB SPL meter .I have two buttons 1. play song 2. display decibel value . When I click on the Play song button it is playing the song. My question is while playing the sound I have to display the sound value in decibels which comes from iPhone . I have searched in the google . But I am not getting any basic ideas to start this app . Please give me idea to do this . Let me know if my question not clear . </p>