Related Clues:

• Sound made by sleeper
• Make noises sleeping
• Noise made while asleep
• It's the last thing one wants to hear at night in broken Norse
• A whistle may follow it in cartoons
• Annoying sleep sound
• Annoyed about note that's heard in the night
• "SKN-X-X!" in comics
• One way to annoy one's spouse
• Certain night noise
• Boring thing, so to speak
• Poles stoned and sound asleep!
• You might wake up to one
• Night annoyance
• Nighttime annoyance