Too much coffee can cause you to hear things that are not there! According to research at Victorian University coffee lovers are three times more likely to see or hear imaginary things than non-coffee drinkers. Ninety-two people with varied caffeine-intake and stress levels were tested.
Subjects thought they were doing hearing tests and were initially subjected to Bing Crosby singing “White Christmas.” Then they were played three minutes of static hiss – or white noise – and asked to press a buzzer if they heard snippets of “White Christmas” – which there weren’t. On average, low-caffeine subjects heard it once. But coffee guzzlers buzzed three times.