Here are a few things to check:
1) On your LabPad, click on the sound icon, on the top-right and make sure sounds are enabled: 🔉

2) Check if your computer's sound is muted or the volume is set very low:

3) Check your browser settings and make sure that the audio is not muted. You can do this by right-clicking on the tab with your simulation and then selecting the "Unmute site" option:

If the simulation still has no sound after doing all the troubleshooting steps above, try to switch browsers (Chrome to Mozilla , Mozilla to Chrome) and check if the simulation will have sounds in a different browser.
Please do not hesitate to reach out to our support team if you have any questions or are in need of assistance.