如何在不录制声音的情况下使用iPhone的内置麦克风绘制大气中分贝级别的声音?

我想绘制通过iPhone内置麦克风听到的大气中分贝级别的声音.我不想录制要绘制的声音.我想要一个声级指示器，并带有一个图形，该图形经常指示相对于声音的分贝级.我该怎么办?

I want to plot the decibel level of the sound in the atmosphere that hearing through the iPhone's inbuilt mic. I don't want to record the sound to plot. I want a sound level indicator, with a graph that frequently indicates the decibel level with respect to the sound. How can I do this?