While using Kennel Connection, there is no sound for popups, error messages or when something is clicked incorrectly.
There is no setting in KC to adjust sound and it has no control over it.
Be sure your volume is not muted or turned down low. Reboot the computer to see if that resolves the issue.
Another step is to open KC, then right click on the speaker icon on your task bar and select Volume Mixer. if KC is listed, try raising the volume.
If neither of these helps, you will need a local technician to troubleshoot the issue.