Judging by the look of the circuit, I am guessing that the mic is triggering the 393 comparator,
With a signal output instruction. One single channel output. low level output signal.
When there is sound output low, lights lit. Can be used for voice-activated lights, with light sensors make a sound and light alarm, and voice control, voice detection occasions.
From the very vague product description given, it appears that output = LOW when there is sound present and vice versa.
From its spec, it appears that the 5V pin can take voltage : DC4-6V to supply the module. You connect the 5V from the Arduino board to the 5V pin on the module and GND to GND of Arduino. You read the signal on the OUT pin using the Arduino, LOW = sound present and HIGH = no sound.