Hi auldblurk,
Please make sure your browser is up to date and try whether clearing your browser cache resolves the issue.
https://www.flyordie.com/games/help/support/clearcache.html
You can also test whether the sound works when using a different browser.
If none of this helps, please contact FlyOrDie’s technical support
https://www.flyordie.com/s/contactSupport.html?portal=flyordie_com&lang=en
and include details about the device you’re using (PC, tablet, phone .. ) and, if possible, the operating system.
Kind regards,
John