The Bristol Hum

For decades people in Bristol have reported hearing a persistent low frequency hum, it made headlines in the 70's with one newspaper asking "Have you heard the Hum?" Almost 800 people said they had. Various sources have been blamed but now Dr David Baguley, Head of Audiology at Addenbrooke's Hospital in Cambridge says over-sensitive hearing may be to blame.
Read more about the hum on the BBC website