The Hum Phenomenon Explained by Low-Frequency Tinnitus

The mysterious worldwide phenomenon known as The Hum may often originate within the auditory system itself, rather than from external sources. Researchers at the Norwegian University of Science and Technology (NTNU) investigated the persistent, low-frequency sound reported by two to four percent of the global population. Their findings suggest that for most individuals, The Hum is a form of low-frequency tinnitus.

The research team, led by Professor Markus Drexl, studied 28 individuals in Germany who reported hearing The Hum. They explored two primary hypotheses: that The Hum was an objectively measurable external sound, or that it was produced internally by the ear. Tests revealed that most participants did not possess exceptional low-frequency hearing, nor did their inner ears produce measurable low-frequency sounds known as oto-acoustic emissions.

While a small number of people might have unusually sensitive low-frequency hearing, the study indicates that for the majority, The Hum is a subjective experience. Tinnitus is the perception of sound in the ears or head without an external source. It can be temporary or persistent. Individuals often initially attribute the sound to their surroundings before realizing its internal origin.

Drexl's team concluded that low-frequency tinnitus is the most probable explanation for many cases of The Hum. This understanding is crucial for assessing the impact of low-frequency sounds and infrasound, which are below 20 hertz. More research is needed to fully comprehend how the human auditory system processes these low-frequency ranges.