Sound sensor only give spike even if the volume stays the same

[blaydator]

Hi,

I am using the grove sound sensor with an arduino mkr wifi 1010 and the connector carrier.

The issue is that if I start playing a noise at a constant level, I only got a spike then the output value drops back to near 0. I was expecting that the sensor would give me the actual sound intensity, but it looks like it measure only increase of sound intensity.

I have used the following code (provided from the site)

const int pinAdc = A0;
 
void setup()
{
    Serial.begin(115200);
    //Serial.println("Grove - Sound Sensor Test...");
}
 
void loop()
{
    long sum = 0;
    for(int i=0; i<32; i++)
    {
        sum += analogRead(pinAdc);
    }
 
    sum >>= 5;
 
    Serial.println(sum);
    delay(10);
}

Here is the output :

Any ideas why the output value doesn’t stay “high” like the sound volume actually is ?