The widely available much simpler boards containing just the small electret mics used in this device, with an amplifier, are good for little more than listening for a loud noise against a quieter background. This device gives a reasonable approximation to sound measured in decibels and it's trivially easy to use because of its analog voltage output that's linearly related to sound in units of dBA. If you really want to monitor sound levels with Arduinos, this is the way to do it.