Encourage students to be careful when using sound blocks in Scratch that don’t have durations, as these blocks start sounds immediately rather than waiting until the first sound is done.

  • The code on the left will start playing the "meow" sound three times, but you’ll only hear it once because the blocks will get started one after the other (without letting each one finish playing).
  • Instead, students should use the "until done" sound block so that the sounds execute fully, one after another, as shown in the example code on the right.
  • play sound (meow) 3 times on the left and play sound (meow) until done 3 times on the right

More about this tip

External Source
Colleen Lewis' CS10K Scratch Webinar