Everything old is indeed new again, including fears that prolonged exposure to loud music from portable-media devices can lead to significant hearing loss. Northwestern University audiologist Dean Garstecki has issued a warning to the roughly 37 million iPod owners to turn down their tunes–or else.[Take it from someone who knows from personal experience, invest in noise-canceling headphones and turn down the volume, otherwise you’ll be saying, “What?” to everything your partner says.–Ed.]