I have the opposite of low hums, I hear incredibly high-pitched sounds. This video contains one of those frequencies. CRT monitors and other tube TVs are incredibly loud to me even if the volume is off.

same here, tinnitus at 16 KHz. i guess this comes primarily from the power grid, because when i measure my body skin voltage versus power ground, via microphone port of a smartphone and spectrogram app, then i see the noise around 16 KHz. i guess the source are power electronics connected to the power grid, especially IGBT transistors which have a working frequency around 16 KHz. i spent 2000 euros on EMF shielding for my bedroom (YShield HNV80), but that can only shield high frequencies like 2.4 GHz wifi, but not the low frequencies from the power grid - 50 Hz to 16 KHz. i started hearing this after a LSD trip... expanding ones consciousness in a bad setting is a bad idea