Try another headset on the laptop and kindle just to verify the symptoms: i.e., one ear works on laptop, both ears work on kindle.
What OS on laptop? Windows has numerous audio related configuration settings. Right click the small speaker icon and look through all of the menus, windows, tabs, and properties settings.
The built-in Windows troubleshooters may find and fix something.
Or you can reinstall the applicable audio drivers.
Key is to determine if the problem source is configuration, software/driver, or hardware.