This extension shows a notifications for latest new/top stories from Hackernews.
HNDN is a chrome extension that brings you latest top/new stories from Hacker News as soon as they arrive. You can choose 8 different notification sounds and set auto-clear timing.
If the extension does not run in the background automatically, go to Settings-> Show advanced settings -> System -> Tick: 'Continue running background apps when Google Chrome [or chromium] is closed'.