Detecting sound opens up a whole range of possibilities for your Arduino, so Marc designed our new Microphone Sound Input Module to provide two outputs: one providing the raw audio waveform, and one providing the sound pressure level (SPL).
The two outputs provide independent access to either the raw signal waveform (the MIC output) or the sound pressure level (the SPL output) to provide maximum flexibility in your projects. If you want to process the audio waveform directly you can use the MIC output, or if you just want to detect sound level (for example, to detect noise above a certain threshold) you can use the SPL output.
You'll notice that near the top right corner is an LED labeled "DETECT", which is linked to the SPL output and illuminates proportionally to detected sound pressure. Perfect for quick visual feedback that it's picking something up. To verify that the module is working you can just supply power and make a noise - you'll immediately see the response on the LED!
See how to hook it up in our Microphone Sound Input Module Quickstart Guide.