That’s an interesting observation. If it’s coming from within you , and you hear it more often when you’re dehydrated - could be because dehydration affects tissue density. And of course the density of any material affects sound transfer. And of course the density of any material affects sound transfer. I would think living tissue would have the same characteristics.
There is a dehydration test of pinching your skin above your thumb joint. If you do this often enough you could probably use this to gauge your hydration level.
In my past experience of hearing Various buzzing noises, and even hearing my heartbeat in my left ear while laying down - that Did not change within the various levels of hydration. I’ve been very dehydrated in the past also after outdoor competition.
That said, we are all different and where our arteries, veins and nerves are intertwined are all a little different.
Post Edited (astroman) : 8/8/2022 11:57:33 PM (GMT-7)