In the city of Taos, New Mexico residents were puzzled when many heard a low-frequency hum in the 1990s. Described as annoying buzzing, buzzing, and even whirring, the annoying noise began to confuse and frustrate the 2% of the population who could hear it.
Although the researchers studied the phenomenon, they were unable to identify the source of the noise. Some began to believe that it was caused by hysteria, suggesting that those who heard the sound only heard it because they thought they could instead of having a real sound while others thought it was through unusual acoustics were caused. The excitement could also be heard in other parts of the US, Canada, the UK and Australia.