Possible Clues:

• Each pair turns up on audition sites?
• Listen to Cockney promotions? Not with these!
• They'll stop you getting anything, by the sound of them
• They stop racket abuse — Sharapova temper finally blows
• Noise-reduction devices
• Mufflers are incredibly soft on appropriate parts of the body
• Hears endless adverts? Not with these!
• They keep noise out
• Complicated gears pull all but the end organ stops?
• Pieces of wax, perhaps