Sound detector - signal amplification

Other Hardware Audio
7 
const int numReadings = 100;
int readings[numReadings];      
int readIndex = 0;              
int total = 0;                 
int average = 0;               
int inputPin = A0;

void setup() {
  
  Serial.begin(9600);
  for (int thisReading = 0; thisReading < numReadings; thisReading++) {
    readings[thisReading] = 0;
  }
}

void loop() {

  total = total - readings[readIndex];
  readings[readIndex] = analogRead(inputPin);
  total = total + readings[readIndex];
  readIndex = readIndex + 1;
  
  if (readIndex >= numReadings) {
    readIndex = 0;
  }

  average = total / numReadings;
  Serial.println(average);
  delay(100);       
}