The experiment file for Speed of Sound (activity 24) supplied with Logger Pro 3.1 and 3.2 is flawed. It collects data immediately instead of waiting for the sound to start.
To fix the file, enable triggering with a level of 2.6 to 2.8. Attached is a fixed experiment file if you’re not comfortable modifying the existing file.
Updating Logger Pro to version 3.3 or newer will also fix the issue.
If you are having trouble getting a short, sharp sound, try a dog training clicker. These make a brief click that is perfect for this activity. Look for a clicker at a pet supply store; they cost only a few dollars.
See also:
What is the best sound to use for the speed of sound experiment?