Simple Arduino Game using SoundDetector

#define button 11 //Start button
#define _signal 12 //Signal from Sound Sensor
#define notifyLED 13  // When starting, notification LED is ON

const int LED[9] = {2, 3, 4, 5, 6, 7, 8, 9, 10}; //Using nine LEDs

void setup() {

  int i;
    
  pinMode(_signal, INPUT);
  pinMode(button, INPUT);
  pinMode(notifyLED, OUTPUT);
  for(i = 0; i < 9; i++) pinMode(LED[i], OUTPUT);

  digitalWrite(notifyLED, HIGH);
  for(i = 0; i < 9; i++) digitalWrite(LED[i], HIGH); // HIGH is off
    
  Serial.begin(9600); //Moniter Serial initialization
  
}

void loop() {

  int check, t, i;
  
  t = 10, check = 0;
    
  digitalWrite(notifyLED, HIGH);
    
  if(digitalRead(button))
  {
    while(digitalRead(button));
    
    for(i = 0; i < 9; i++) digitalWrite(LED[i], HIGH); //LED initialization

    Serial.println("Initialized!");
      
    digitalWrite(notifyLED, LOW);

    // checking
    do
    {
      if(digitalRead(_signal) == HIGH) check++;
      else check = 0; 
  
      delay(500);
    }while(check != 2);
  
    while(check)
    {
      t++; 
      delay(100);
           
      digitalWrite(LED[(t/20) - 1], LOW); //LED is ON every 2sec(100 * 20 = 2000ms)
           
      if(digitalRead(_signal) == LOW) check = 0;
    }
  
    Serial.println(t/10); //Measurement time
    
  }
  
  
}