It's currently just... ugh, unpleasant. And not like a "ping" at all. Can haz change to normal pling sound from SO?
Sorry, all sites that have a chat.stackexchange.com home URL have that noise.
There are userscripts to change it that you can install on your browser (see StackApps.) or you can mute all sounds from the chatroom and, instead, rely on desktop notifications.
To turn off all sounds in a chatroom, just click the speaker icon next to the chatroom name.