> Would "the hum" not be noticed in a lot more areas if it were caused by jet engines?
Yes, I agree hence the way I worded the starting of the comment. It was more an observation that there is a lot more noise going on than is immediately obvious and noticeable.
Regarding these hums some people are reporting, given that they say ear plugs if anything increase the effect I think it is likely internally generated like the various causes of tinnitus. Possibly some infra-sound/vibration is directly detectable by some people in a similar way to magmatism is by some animals and supposedly some people. A second thought is it could be triggering / resonating something in the ear so you are physically hearing the sounds, like when you rub your eyes you see flashes. Thirdly perhaps it is purely psychological.
I've not read much about the hum phenomena and not knowingly personally experienced it my thoughts are just that, thoughts.
Yes, I agree hence the way I worded the starting of the comment. It was more an observation that there is a lot more noise going on than is immediately obvious and noticeable.
Regarding these hums some people are reporting, given that they say ear plugs if anything increase the effect I think it is likely internally generated like the various causes of tinnitus. Possibly some infra-sound/vibration is directly detectable by some people in a similar way to magmatism is by some animals and supposedly some people. A second thought is it could be triggering / resonating something in the ear so you are physically hearing the sounds, like when you rub your eyes you see flashes. Thirdly perhaps it is purely psychological.
I've not read much about the hum phenomena and not knowingly personally experienced it my thoughts are just that, thoughts.