Ding for Southwest Airlines on a IMac

Ever since I got a IMac, I have not been able to download ding. I have called apple support and Southwest Airlines, but have had no luck. Any suggestions?

They aren't dinging much these days anyway. You aren't missing anything.

It's been so long since I've heard a ding that I assumed my husband uninstalled it. Nope. It's still here. It just never dings anymore.