how to make beep function sound better

Question

I'm trying to make a morse code program that you can use to convert words to morse code. I'm using the Beep function, but the space in-between each beep is either too long, or changes from beep to beep. I tried using the sleep function, but it didn't work. Is there any way to make the beeps faster or more consistent?

Here's a sample for the letter S

int main() {

  Beep(400,500);
  Beep(400,500);
  Beep(400,500);
  return 0;
}