Using the pop-out menu (by selecting the orange icon, 4th down - FLOW), I select the LOOP block (2nd from left - others are WAIT, SWITCH, and STOP blocks).
When the LOOP block is first dropped, it is set for "Forever" - it will run until you manually end it. Using the drop-down menu, you can select sensors to determine if the loop breaks.
Now I've configured the LOOP for a count of 5. I've also dropped in a SOUND block - when the program runs, the configured sound or tone will play 5 times before the loop breaks.
I've added a STOP block just to be complete. The program will stop without it because it's set to loop 5 times. Just an old programming habit of actually STOPping the program.
For this image, I've just shown you how the LOOP block is set to be triggered by a SOUND sensor. You can set the limits (high or low) for triggering the break.