5PCS KY-037 High Sensitivity Microphone Sound Voice Detection Sensor Module Compatible with Arduino Raspberry Pi AVR PIC

If you're looking for an easy way to detect audio volume level, don't bother with these - you should consider something like a DFRobot SEN0232 instead.The reason I say this is that these KY-037 are very difficult to calibrate, and inconsistent. The voltage that these produce includes peaks and dips, so you've got to abs() them to make the value always positive.Once you do that, you've then got to calibrate it (using the onboard potentiometer) against a known source. A mobile phone + sound level app is sufficient for rough measurements. Even once you've done that though, the values you get one day may be different the next day, even if your calibration source says they're the same.Some people have said that the potentiometer doesn't affect the analogue output, but this is incorrect. There is a measurable difference in the output voltage when turning the potentiometer. You turn it far enough, and it'll always report ~4098mv. Turn it the other direction, and it'll always report very low values (~100mv, but it varies slightly).I'm sure the digital output of this would be great as a 'clap detector', or a noise-threshold detectr, but that's all I can recommend it for. This product is simply unsuitable for even rudimentary measurements of an analogue sound level.

When i ordered them they worked well, and they're easy to use