Audio Measurement

I am looking to have a project with a story board that will measure an audio input and calculate the highest power level, average power level, highest decibel level, and average decibel level for a given length of time. I need to have a variable that allows me to specify the length of time to measure the audio input. The user interface should be a meter attached to the input sound that increases and decreases with the input sound level. It only needs to have one button that when pressed will measure the sound for the previously determined length of time, display the sound levels on a meter while recording and play back the sound when the input length of time is finished. I would like to be able to add my own background image, button and meter for the user interface so I should be able to change the images associated with the user interface without having to recode. So as a break down. 1. The user interface will have a background image, button, and meter. 2. I would like to be able to change this images in the project without recoding. 3. When the user presses the button it should record the incoming audio for a predetermined length of time, displaying the audio level changes on the meter. 4. when the predetermined time is up it will play back the recorded sound and display the results of the highest power level, average power level, highest decibel level, average decibel level. 5. When the button is pressed again all previously recorded values and audio should be reset 6. Memory should be managed according to Apple's best practices.